CVE-2026-73636

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Apache HTTP Server is a powerful and flexible HTTP/1.1 compliant web server.

Security Fix(es):

Missing authentication checks in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause a denial of service (forced re-authentication) via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck .

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-48005)

Internal state files accessible to external parties in mod_dav_fs in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows a remote client to read WebDAV dead properties of resources it cannot author via a GET request for the .DAV state directory

This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.(CVE-2026-58415)

Out-of-bounds Write vulnerability in Apache HTTP Server on Windows while processing paths with 8.3 names that may grow when expanded.

This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.(CVE-2026-59685)

Improper Privilege Management vulnerability in Apache HTTP Server's mod_ssl via SSLRequire and file-related expressions.

This issue affects Apache HTTP Server: from 2.4.0 through 2.4.68.(CVE-2026-59797)

Improper validation of FTP PASV reply address in mod_proxy_ftp in Apache Software Foundation Apache HTTP Server through 2.4.68 on all platforms allows, in forward proxy configurations, an untrusted FTP server to cause the proxy to open a data connection to an arbitrary third-party host via a crafted PASV response.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-63045)

Stack-based buffer overflow in mod_vhost_alias in Apache Software Foundation Apache HTTP Server through 2.4.68 on all platforms allows a remote client to cause a denial of service or potentially execute arbitrary code via an HTTP request with a Host header exceeding 8192 bytes when VirtualDocumentRoot uses a hostname format specifier and LimitRequestFieldSize is raised above the default.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-63292)

A NULL pointer dereference in mod_xml2enc in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an untrusted backend server to cause a denial of service via a proxied response with a charset whose conversion partially succeeds then fails.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-63686)

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') response smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi and a crafted uwsgi response with Transfer-Encoding.

This issue affects Apache HTTP Server: from 2.4.30 through 2.4.68.(CVE-2026-63718)

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73636)

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73637)

Path equivalence: '/./' (single dot directory) vulnerability in Apache HTTP Server's mod_userdir module when configured with absolute non-wildcard UserDir directive (the 2nd form…

Apache HTTP Server is a powerful and flexible HTTP/1.1 compliant web server.

Security Fix(es):

Missing authentication checks in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause a denial of service (forced re-authentication) via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck .

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-48005)

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73636)

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73637)

Apache HTTP Server is a powerful and flexible HTTP/1.1 compliant web server.

Security Fix(es):

Missing authentication checks in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause a denial of service (forced re-authentication) via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck .

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-48005)

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73636)

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73637)

Apache HTTP Server is a powerful and flexible HTTP/1.1 compliant web server.

Security Fix(es):

Missing authentication checks in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause a denial of service (forced re-authentication) via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck .

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-48005)

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73636)

Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.(CVE-2026-73637)

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: httpd: HTTP response smuggling via crafted Transfer-Encoding response in mod_proxy_uwsgi (CVE-2026-63718)

• httpd: httpd: Denial of Service via integer overflow in mod_dav_fs (CVE-2026-93546)

• httpd: httpd: Authentication state corruption via concurrent Digest authentication requests (CVE-2026-73637)

• httpd: httpd: unauthorized connection to arbitrary hosts via crafted FTP PASV response (CVE-2026-63045)

• httpd: httpd: Arbitrary code execution via oversized Host header in mod_vhost_alias (CVE-2026-63292)

• httpd: httpd: mod_heartmonitor: Denial of Service via NULL pointer dereference (CVE-2026-46729)

• httpd: httpd: Authentication bypass via credential replay in mod_auth_digest (CVE-2026-73636)

• httpd: httpd: Denial of Service via charset conversion failure in mod_xml2enc (CVE-2026-63686)

• httpd: httpd: Denial of service via forged Authorization headers in mod_auth_digest (CVE-2026-48005)

• httpd: httpd: Denial of Service via mod_rewrite lookahead (CVE-2026-56154)

• httpd: httpd: Denial of Service via heap-based buffer overflow in mod_charset_lite (CVE-2026-56153)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: httpd: HTTP response smuggling via crafted Transfer-Encoding response in mod_proxy_uwsgi (CVE-2026-63718)

• httpd: httpd: Denial of Service via integer overflow in mod_dav_fs (CVE-2026-93546)

• httpd: httpd: Authentication state corruption via concurrent Digest authentication requests (CVE-2026-73637)

• httpd: httpd: unauthorized connection to arbitrary hosts via crafted FTP PASV response (CVE-2026-63045)

• httpd: httpd: Arbitrary code execution via oversized Host header in mod_vhost_alias (CVE-2026-63292)

• httpd: httpd: mod_heartmonitor: Denial of Service via NULL pointer dereference (CVE-2026-46729)

• httpd: httpd: Authentication bypass via credential replay in mod_auth_digest (CVE-2026-73636)

• httpd: httpd: Denial of Service via charset conversion failure in mod_xml2enc (CVE-2026-63686)

• httpd: httpd: Denial of service via forged Authorization headers in mod_auth_digest (CVE-2026-48005)

• httpd: httpd: Denial of Service via mod_rewrite lookahead (CVE-2026-56154)

• httpd: httpd: Denial of Service via heap-based buffer overflow in mod_charset_lite (CVE-2026-56153)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: mod_auth_digest: timing attack allows a bypass of digest authentication (CVE-2026-33006)

• httpd: httpd: HTTP response smuggling via crafted Transfer-Encoding response in mod_proxy_uwsgi (CVE-2026-63718)

• httpd: httpd: Denial of Service via integer overflow in mod_dav_fs (CVE-2026-93546)

• httpd: httpd: Authentication state corruption via concurrent Digest authentication requests (CVE-2026-73637)

• httpd: httpd: unauthorized connection to arbitrary hosts via crafted FTP PASV response (CVE-2026-63045)

• httpd: httpd: Arbitrary code execution via oversized Host header in mod_vhost_alias (CVE-2026-63292)

• httpd: httpd: mod_heartmonitor: Denial of Service via NULL pointer dereference (CVE-2026-46729)

• httpd: httpd: Authentication bypass via credential replay in mod_auth_digest (CVE-2026-73636)

• httpd: httpd: Denial of Service via charset conversion failure in mod_xml2enc (CVE-2026-63686)

• httpd: httpd: Denial of service via forged Authorization headers in mod_auth_digest (CVE-2026-48005)

• httpd: httpd: Denial of Service via mod_rewrite lookahead (CVE-2026-56154)

• httpd: httpd: Denial of Service via heap-based buffer overflow in mod_charset_lite (CVE-2026-56153)

Bug Fix(es) and Enhancement(s):

• mod_proxy_hcheck: passing health check does not recover worker from its standard error state (PROXY_WORKER_IN_ERROR) (JIRA:Rocky Linux-256797)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: httpd: HTTP response smuggling via crafted Transfer-Encoding response in mod_proxy_uwsgi (CVE-2026-63718)
• httpd: httpd: Denial of Service via integer overflow in mod_dav_fs (CVE-2026-93546)
• httpd: httpd: Authentication state corruption via concurrent Digest authentication requests (CVE-2026-73637)
• httpd: httpd: unauthorized connection to arbitrary hosts via crafted FTP PASV response (CVE-2026-63045)
• httpd: httpd: Arbitrary code execution via oversized Host header in mod_vhost_alias (CVE-2026-63292)
• httpd: httpd: mod_heartmonitor: Denial of Service via NULL pointer dereference (CVE-2026-46729)
• httpd: httpd: Authentication bypass via credential replay in mod_auth_digest (CVE-2026-73636)
• httpd: httpd: Denial of Service via charset conversion failure in mod_xml2enc (CVE-2026-63686)
• httpd: httpd: Denial of service via forged Authorization headers in mod_auth_digest (CVE-2026-48005)
• httpd: httpd: Denial of Service via mod_rewrite lookahead (CVE-2026-56154)
• httpd: httpd: Denial of Service via heap-based buffer overflow in mod_charset_lite (CVE-2026-56153)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: httpd: HTTP response smuggling via crafted Transfer-Encoding response in mod_proxy_uwsgi (CVE-2026-63718)
• httpd: httpd: Denial of Service via integer overflow in mod_dav_fs (CVE-2026-93546)
• httpd: httpd: Authentication state corruption via concurrent Digest authentication requests (CVE-2026-73637)
• httpd: httpd: unauthorized connection to arbitrary hosts via crafted FTP PASV response (CVE-2026-63045)
• httpd: httpd: Arbitrary code execution via oversized Host header in mod_vhost_alias (CVE-2026-63292)
• httpd: httpd: mod_heartmonitor: Denial of Service via NULL pointer dereference (CVE-2026-46729)
• httpd: httpd: Authentication bypass via credential replay in mod_auth_digest (CVE-2026-73636)
• httpd: httpd: Denial of Service via charset conversion failure in mod_xml2enc (CVE-2026-63686)
• httpd: httpd: Denial of service via forged Authorization headers in mod_auth_digest (CVE-2026-48005)
• httpd: httpd: Denial of Service via mod_rewrite lookahead (CVE-2026-56154)
• httpd: httpd: Denial of Service via heap-based buffer overflow in mod_charset_lite (CVE-2026-56153)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

The httpd packages provide the Apache HTTP Server, a powerful, efficient, and extensible web server.

Security Fix(es):

• httpd: mod_auth_digest: timing attack allows a bypass of digest authentication (CVE-2026-33006)
• httpd: httpd: HTTP response smuggling via crafted Transfer-Encoding response in mod_proxy_uwsgi (CVE-2026-63718)
• httpd: httpd: Denial of Service via integer overflow in mod_dav_fs (CVE-2026-93546)
• httpd: httpd: Authentication state corruption via concurrent Digest authentication requests (CVE-2026-73637)
• httpd: httpd: unauthorized connection to arbitrary hosts via crafted FTP PASV response (CVE-2026-63045)
• httpd: httpd: Arbitrary code execution via oversized Host header in mod_vhost_alias (CVE-2026-63292)
• httpd: httpd: mod_heartmonitor: Denial of Service via NULL pointer dereference (CVE-2026-46729)
• httpd: httpd: Authentication bypass via credential replay in mod_auth_digest (CVE-2026-73636)
• httpd: httpd: Denial of Service via charset conversion failure in mod_xml2enc (CVE-2026-63686)
• httpd: httpd: Denial of service via forged Authorization headers in mod_auth_digest (CVE-2026-48005)
• httpd: httpd: Denial of Service via mod_rewrite lookahead (CVE-2026-56154)
• httpd: httpd: Denial of Service via heap-based buffer overflow in mod_charset_lite (CVE-2026-56153)

Bug Fix(es) and Enhancement(s):

• mod_proxy_hcheck: passing health check does not recover worker from its standard error state (PROXY_WORKER_IN_ERROR) (JIRA:RHEL-256797)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.

Authentication bypass by capture-replay in mod_auth_digest in Apache Software Foundation Apache HTTP Server 2.4.x on all platforms allows a man-in-the-middle (MITM) attacker to replay captured digest authentication credentials via crafted requests that trigger garbage collection of the client's shared memory entry when AuthDigestNonceLifetime is set to 0.

Users are recommended to upgrade to version 2.4.69, which fixes this issue.

• SECURITY UPDATE: use-after-free in mod_rewrite lookahead variables
  • debian/patches/CVE-2026-56154.patch: copy the Vary value gathered during a LA-U/LA-F lookahead into the main request pool before the sub-request is destroyed in modules/mappers/mod_rewrite.c.
  • CVE-2026-56154
• SECURITY UPDATE: buffer overflow in mod_vhost_alias interpolation
  • debian/patches/CVE-2026-63292.patch: reject a VirtualDocumentRoot expansion segment that does not fit the buffer in modules/mappers/mod_vhost_alias.c.
  • CVE-2026-63292
• SECURITY UPDATE: crash in mod_xml2enc on incomplete input
  • debian/patches/CVE-2026-63686.patch: handle APR_INCOMPLETE from the converter and pass the rest raw after a conversion failure instead of reusing a NULL converter in modules/filters/mod_xml2enc.c.
  • CVE-2026-63686
• SECURITY UPDATE: digest replay and use-after-free in mod_auth_digest
  • debian/patches/CVE-2026-73636_CVE-2026-73637.patch: enforce one-time nonce and nonce-count handling, and only use shared client entries under the client lock, in modules/aaa/mod_auth_digest.c.
  • CVE-2026-73636
  • CVE-2026-73637

• CVE-2026-63718: fix mod_proxy_uwsgi response smuggling by dropping hop-by-hop headers from the backend response
• CVE-2026-73636: fix mod_auth_digest one-time nonce replay
• CVE-2026-73637: fix mod_auth_digest use-after-free of shared client entries on concurrent requests

• CVE-2026-63718: fix mod_proxy_uwsgi response smuggling via hop-by-hop headers from the backend
• CVE-2026-73636: fix mod_auth_digest one-time nonce replay
• CVE-2026-73637: fix mod_auth_digest use-after-free on concurrent requests
• CVE-2026-48005: fix mod_auth_digest forced re-authentication via forged Authorization headers with AuthDigestNcCheck
• mod_auth_digest: configs using "AuthDigestQop none" or the "authdigest-opaque" Mutex type no longer start (the shipped manual still documents "AuthDigestQop none"); RFC 2069 clients (no qop) are refused; no Authentication-Info on 401/407; 503, or 401 without a challenge, if no client entry fits in shared memory; log ids AH01767, AH01771, AH01772, AH01792 and AH01793 are removed
• mod_auth_digest: after a reload (graceful restart) a captured request is accepted once more under AuthDigestNonceLifetime 0 or AuthDigestNcCheck; only a full restart invalidates it (fixed upstream only in trunk f4c4160fbf, not in 2.4.69)

• SECURITY UPDATE: one-time nonce replay and use-after-free in mod_auth_digest
  • debian/patches/CVE-2026-73636_CVE-2026-73637.patch: accept a one-time nonce or nonce-count only when it is newer than the one last recorded for the client, and send a stale challenge when the client entry is no longer known, in client_update_nonce() called from check_and_record_nonce(); access client entries only while holding client_lock, in modules/aaa/mod_auth_digest.c. AuthDigestQop now accepts only "auth", and requests without qop=auth are rejected.
  • CVE-2026-73636
  • CVE-2026-73637

• CVE-2026-63718: mod_proxy_uwsgi: drop hop-by-hop headers from the backend response
• CVE-2026-73636: mod_auth_digest: accept a one-time nonce only once, also when the client entry was garbage collected
• CVE-2026-73637: mod_auth_digest: don't use a client entry outside the client lock
• CVE-2026-48005: mod_auth_digest: track the nonce-count per nonce and record it only for a fully verified request
• mod_auth_digest: configs using "AuthDigestQop none" or the "authdigest-opaque" Mutex type no longer start ("AuthDigestQop none" in .htaccess: 500; the shipped manual still documents it); RFC 2069 clients (no qop) are refused; with AuthDigestNcCheck On or AuthDigestNonceLifetime 0, 503 if no client entry fits in shared memory; log ids AH01767, AH01771, AH01772, AH01792 and AH01793 are removed
• mod_auth_digest: with AuthDigestNcCheck On, a request that is authenticated twice (e.g. a DirectoryIndex file in its own <Files> section) is refused with 401
• mod_auth_digest: after a reload (also the logrotate one) or a SIGHUP restart a captured request can be accepted once more under AuthDigestNonceLifetime 0 or AuthDigestNcCheck; only stopping httpd (systemctl restart) invalidates it (fixed upstream only in trunk f4c4160fbf, not in 2.4.69)
• CVE-2026-63686: mod_xml2enc: avoid a NULL pointer dereference when a charset conversion fails part way
• CVE-2026-63045: mod_proxy_ftp: reject a PASV reply whose address differs from the control connection peer
• CVE-2026-42528: mod_dav: limit the number of shared locks on a resource
• CVE-2026-93546: mod_dav_fs: cap the property database namespace table at 2048 entries
• CVE-2026-58415: mod_dav_fs: deny access to the .DAV state directory for all methods, including GET
• CVE-2026-59797: mod_ssl: don't allow file() and filesize() in SSLRequire from .htaccess files
• CVE-2026-79768: mod_userdir: reject "." as a user name

• CVE-2026-42356: do not run the target of a CGI internal redirect with the handler derived from the CGI request's trusted content type
• CVE-2026-63686: fix mod_xml2enc NULL pointer dereference when a charset conversion partially succeeds and then fails
• CVE-2026-63718: fix mod_proxy_uwsgi response smuggling via backend Transfer-Encoding by dropping hop-by-hop response headers
• CVE-2026-73636: fix mod_auth_digest one-time nonce replay
• CVE-2026-73637: fix mod_auth_digest use-after-free of shared client entries on concurrent requests
• CVE-2026-48005: fix mod_auth_digest forced re-authentication via forged Authorization headers with AuthDigestNcCheck
• mod_auth_digest: configs using "AuthDigestQop none" or the "authdigest-opaque" Mutex type no longer start (the shipped manual still documents "AuthDigestQop none"); RFC 2069 clients (no qop) are refused; with AuthDigestNcCheck On or AuthDigestNonceLifetime 0, 503 if no client entry fits in shared memory; log ids AH01767, AH01771, AH01772, AH01792 and AH01793 are removed
• mod_auth_digest: with AuthDigestNcCheck On, a request that is authenticated twice (e.g. a DirectoryIndex file in its own <Files> section) is refused with 401
• mod_auth_digest: after a reload (also the logrotate one) or a SIGHUP restart a captured request can be accepted once more under AuthDigestNonceLifetime 0 or AuthDigestNcCheck; only stopping httpd (systemctl restart) invalidates it (fixed upstream only in trunk f4c4160fbf, not in 2.4.69)

Limited RCE for some internal redirects to non-CGI files in CGI directories. (CVE-2026-42356) mod_dav shared lock overflow. (CVE-2026-42528) mod_heartmonitor denial of service. (CVE-2026-46729) mod_session: Session cookie not removed during internal redirect. (CVE-2026-47360) mod_auth_digest reauthentication attack. (CVE-2026-48005) mod_charset_lite: Heap overflow in finish_partial_char. (CVE-2026-56153) mod_rewrite use-after-free via %{LA-U:HTTP:...}. (CVE-2026-56154) mod_proxy_html: crash in dump_content. (CVE-2026-56449) mod_http2 use-after-free / wild write via shared session->bbtmp re-entrancy. (CVE-2026-57941) mod_dav_fs property database read access. (CVE-2026-58415) Out-of-Bounds Write in ap_directory_walk() Canonical-Name Rewrite on CASE_BLIND_FILESYSTEM. (CVE-2026-59685) mod_ssl SSLRequire allows .htaccess ap_expr file-function. (CVE-2026-59797) mod_proxy_ftp PASV address handling. (CVE-2026-63045) mod_vhost_alias stack overflow. (CVE-2026-63292) mod_xml2enc crash on charset conversion failure. (CVE-2026-63686) mod_proxy_uwsgi Transfer-Encoding response smuggling. (CVE-2026-63718) mod_auth_digest one-time-nonce replay attack. (CVE-2026-73636) mod_auth_digest DoS attack. (CVE-2026-73637) mod_userdir information disclosure. (CVE-2026-79768) mod_dav_fs namespace overflow. (CVE-2026-93546)

Root has patched CVE-2026-73636 in the apache2 package for Root:Debian:12. Multiple fixed versions available.

This update for apache2 fixes the following issues:

• CVE-2026-42356: deployment of wrong handler allows target of internal redirects from CGI programs to also be treated as CGI and executed (bsc#1284043).
• CVE-2026-42528: memory calculation bug in mod_dav allows an attacker with permission to create WebDAV locks to crash server child processes (bsc#1284044).
• CVE-2026-46729: NULL pointer dereference in mod_heartmonitor over unicast listener (bsc#1284045).
• CVE-2026-47360: session cookie passed to a backend server when SessionCookieRemove changes across internal redirects (bsc#1284046).
• CVE-2026-48005: missing authentication checks in mod_auth_digest allows an unauthenticated remote client to cause a DoS via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck (bsc#1284047).
• CVE-2026-56153: out-of-bounds write in mod_charset_lite (bsc#1284048).
• CVE-2026-56154: use-after-free in mod_rewrite when using lookahead (%{LA-U:HTTP:...}) (bsc#1284049).
• CVE-2026-57941: use-after-free in mod_http2 via shared session->bbtmp re-entrancy (bsc#1284050).
• CVE-2026-58415: internal state files accessible to external parties in mod_dav_fs allows a remote client to read WebDAV dead properties of resources it cannot author via a GET request for the .DAV state directory (bsc#1284051).
• CVE-2026-59797: improper privilege management in mod_ssl when using SSLRequire and file-related expressions (bsc#1284059).
• CVE-2026-63045: improper validation of FTP PASV reply address in mod_proxy_ftp allows an untrusted FTP server to cause a proxy to open a data connection to an arbitrary third-party host (bsc#1284060).
• CVE-2026-63292: stack-based buffer overflow in mod_vhost_alias allows a remote client to cause a DoS or potentially execute arbitrary code via an HTTP request with a specially crafted Host header (bsc#1284061).
• CVE-2026-63686: NULL pointer dereference in mod_xml2enc allows an untrusted backend server to cause a denial of service via a crafted proxied response (bsc#1284058).
• CVE-2026-63718: inconsistent interpretation of HTTP requests in mod_proxy_uwsgi allows for response smuggling via a crafted uwsgi response with Transfer-Encoding (bsc#1284057).
• CVE-2026-73636: authentication bypass by capture-replay in mod_auth_digest allows a MiTM attacker to replay captured digest authentication credentials via crafted requests (bsc#1284056).
• CVE-2026-73637: use-after-free in mod_auth_digest allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests (bsc#1284055).
• CVE-2026-79768: path equivalence issue in the mod_userdir module when configured with absolute non-wildcard UserDir directive (bsc#1284054).
• CVE-2026-93546: integer overflow in mod_dav_fs allows an authenticated WebDAV client with write access to crash worker processes and persistently corrupt a directory's property database (bsc#1284053).

This update for apache2 fixes the following issues:

• CVE-2026-42356: deployment of wrong handler allows target of internal redirects from CGI programs to also be treated as CGI and executed (bsc#1284043).
• CVE-2026-42528: memory calculation bug in mod_dav allows an attacker with permission to create WebDAV locks to crash server child processes (bsc#1284044).
• CVE-2026-46729: NULL pointer dereference in mod_heartmonitor over unicast listener (bsc#1284045).
• CVE-2026-47360: session cookie passed to a backend server when SessionCookieRemove changes across internal redirects (bsc#1284046).
• CVE-2026-48005: missing authentication checks in mod_auth_digest allows an unauthenticated remote client to cause a DoS via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck (bsc#1284047).
• CVE-2026-56153: out-of-bounds write in mod_charset_lite (bsc#1284048).
• CVE-2026-56154: use-after-free in mod_rewrite when using lookahead (%{LA-U:HTTP:...}) (bsc#1284049).
• CVE-2026-57941: use-after-free in mod_http2 via shared session->bbtmp re-entrancy (bsc#1284050).
• CVE-2026-58415: internal state files accessible to external parties in mod_dav_fs allows a remote client to read WebDAV dead properties of resources it cannot author via a GET request for the .DAV state directory (bsc#1284051).
• CVE-2026-59797: improper privilege management in mod_ssl when using SSLRequire and file-related expressions (bsc#1284059).
• CVE-2026-63045: improper validation of FTP PASV reply address in mod_proxy_ftp allows an untrusted FTP server to cause a proxy to open a data connection to an arbitrary third-party host (bsc#1284060).
• CVE-2026-63292: stack-based buffer overflow in mod_vhost_alias allows a remote client to cause a DoS or potentially execute arbitrary code via an HTTP request with a specially crafted Host header (bsc#1284061).
• CVE-2026-63686: NULL pointer dereference in mod_xml2enc allows an untrusted backend server to cause a denial of service via a crafted proxied response (bsc#1284058).
• CVE-2026-63718: inconsistent interpretation of HTTP requests in mod_proxy_uwsgi allows for response smuggling via a crafted uwsgi response with Transfer-Encoding (bsc#1284057).
• CVE-2026-73636: authentication bypass by capture-replay in mod_auth_digest allows a MiTM attacker to replay captured digest authentication credentials via crafted requests (bsc#1284056).
• CVE-2026-73637: use-after-free in mod_auth_digest allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests (bsc#1284055).
• CVE-2026-79768: path equivalence issue in the mod_userdir module when configured with absolute non-wildcard UserDir directive (bsc#1284054).
• CVE-2026-93546: integer overflow in mod_dav_fs allows an authenticated WebDAV client with write access to crash worker processes and persistently corrupt a directory's property database (bsc#1284053).

This update for apache2 fixes the following issues:

• CVE-2026-42356: deployment of wrong handler allows target of internal redirects from CGI programs to also be treated as CGI and executed (bsc#1284043).
• CVE-2026-42528: memory calculation bug in mod_dav allows an attacker with permission to create WebDAV locks to crash server child processes (bsc#1284044).
• CVE-2026-46729: NULL pointer dereference in mod_heartmonitor over unicast listener (bsc#1284045).
• CVE-2026-47360: session cookie passed to a backend server when SessionCookieRemove changes across internal redirects (bsc#1284046).
• CVE-2026-48005: missing authentication checks in mod_auth_digest allows an unauthenticated remote client to cause a DoS via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck (bsc#1284047).
• CVE-2026-56153: out-of-bounds write in mod_charset_lite (bsc#1284048).
• CVE-2026-56154: use-after-free in mod_rewrite when using lookahead (%{LA-U:HTTP:...}) (bsc#1284049).
• CVE-2026-57941: use-after-free in mod_http2 via shared session->bbtmp re-entrancy (bsc#1284050).
• CVE-2026-58415: internal state files accessible to external parties in mod_dav_fs allows a remote client to read WebDAV dead properties of resources it cannot author via a GET request for the .DAV state directory (bsc#1284051).
• CVE-2026-59797: improper privilege management in mod_ssl when using SSLRequire and file-related expressions (bsc#1284059).
• CVE-2026-63045: improper validation of FTP PASV reply address in mod_proxy_ftp allows an untrusted FTP server to cause a proxy to open a data connection to an arbitrary third-party host (bsc#1284060).
• CVE-2026-63292: stack-based buffer overflow in mod_vhost_alias allows a remote client to cause a DoS or potentially execute arbitrary code via an HTTP request with a specially crafted Host header (bsc#1284061).
• CVE-2026-63686: NULL pointer dereference in mod_xml2enc allows an untrusted backend server to cause a denial of service via a crafted proxied response (bsc#1284058).
• CVE-2026-63718: inconsistent interpretation of HTTP requests in mod_proxy_uwsgi allows for response smuggling via a crafted uwsgi response with Transfer-Encoding (bsc#1284057).
• CVE-2026-73636: authentication bypass by capture-replay in mod_auth_digest allows a MiTM attacker to replay captured digest authentication credentials via crafted requests (bsc#1284056).
• CVE-2026-73637: use-after-free in mod_auth_digest allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests (bsc#1284055).
• CVE-2026-79768: path equivalence issue in the mod_userdir module when configured with absolute non-wildcard UserDir directive (bsc#1284054).
• CVE-2026-93546: integer overflow in mod_dav_fs allows an authenticated WebDAV client with write access to crash worker processes and persistently corrupt a directory's property database (bsc#1284053).

This update for apache2 fixes the following issues:

• CVE-2026-42356: deployment of wrong handler allows target of internal redirects from CGI programs to also be treated as CGI and executed (bsc#1284043).
• CVE-2026-42528: memory calculation bug in mod_dav allows an attacker with permission to create WebDAV locks to crash server child processes (bsc#1284044).
• CVE-2026-46729: NULL pointer dereference in mod_heartmonitor over unicast listener (bsc#1284045).
• CVE-2026-47360: session cookie passed to a backend server when SessionCookieRemove changes across internal redirects (bsc#1284046).
• CVE-2026-48005: missing authentication checks in mod_auth_digest allows an unauthenticated remote client to cause a DoS via forged Authorization headers when Digest authentication is enabled with AuthDigestNcCheck (bsc#1284047).
• CVE-2026-56153: out-of-bounds write in mod_charset_lite (bsc#1284048).
• CVE-2026-56154: use-after-free in mod_rewrite when using lookahead (%{LA-U:HTTP:...}) (bsc#1284049).
• CVE-2026-57941: use-after-free in mod_http2 via shared session->bbtmp re-entrancy (bsc#1284050).
• CVE-2026-58415: internal state files accessible to external parties in mod_dav_fs allows a remote client to read WebDAV dead properties of resources it cannot author via a GET request for the .DAV state directory (bsc#1284051).
• CVE-2026-59797: improper privilege management in mod_ssl when using SSLRequire and file-related expressions (bsc#1284059).
• CVE-2026-63045: improper validation of FTP PASV reply address in mod_proxy_ftp allows an untrusted FTP server to cause a proxy to open a data connection to an arbitrary third-party host (bsc#1284060).
• CVE-2026-63292: stack-based buffer overflow in mod_vhost_alias allows a remote client to cause a DoS or potentially execute arbitrary code via an HTTP request with a specially crafted Host header (bsc#1284061).
• CVE-2026-63686: NULL pointer dereference in mod_xml2enc allows an untrusted backend server to cause a denial of service via a crafted proxied response (bsc#1284058).
• CVE-2026-63718: inconsistent interpretation of HTTP requests in mod_proxy_uwsgi allows for response smuggling via a crafted uwsgi response with Transfer-Encoding (bsc#1284057).
• CVE-2026-73636: authentication bypass by capture-replay in mod_auth_digest allows a MiTM attacker to replay captured digest authentication credentials via crafted requests (bsc#1284056).
• CVE-2026-73637: use-after-free in mod_auth_digest allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests (bsc#1284055).
• CVE-2026-79768: path equivalence issue in the mod_userdir module when configured with absolute non-wildcard UserDir directive (bsc#1284054).
• CVE-2026-93546: integer overflow in mod_dav_fs allows an authenticated WebDAV client with write access to crash worker processes and persistently corrupt a directory's property database (bsc#1284053).

이지웅 discovered that Apache HTTP Server exposed WebDAV property information. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-58415)

Zhen Kong and Charles Vosburgh discovered that Apache HTTP Server did not properly validate FTP server responses. A remote attacker could possibly use this issue to make a forward proxy connect to an arbitrary host. (CVE-2026-63045)

Hyojae Lee and Zhen Kong discovered that Apache HTTP Server incorrectly handled certain HTTP requests. A remote attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-63292)

Lucian Nitescu and Zhen Kong discovered that Apache HTTP Server did not properly handle certain responses from backend servers. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-63686)

Qing Xu discovered that Apache HTTP Server incorrectly interpreted HTTP responses from backend servers. A remote attacker could possibly use this issue to perform HTTP response smuggling attacks. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-63718)

Hyojae Lee discovered that Apache HTTP Server did not properly validate Digest authentication requests. A machine-in-the-middle attacker could possibly use this issue to bypass authentication. (CVE-2026-73636)

Zhen Kong and Darren Carreras discovered that Apache HTTP Server did not properly manage authentication requests. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-73637)

Vlatko Kosturjak discovered that Apache HTTP Server did not properly enforce access restrictions for user directories. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-79768)

Zhen Kong discovered that Apache HTTP Server did not properly handle certain WebDAV requests. An authenticated user could possibly use this issue to cause a denial of service or corrupt WebDAV property data. (CVE-2026-93546)