CVE-2026-33523

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers. This issue affects Apache HTTP Server: from through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

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

Security Fix(es):

An escalation of privilege bug in various modules in Apache HTTP 2.4.66 and earlier allows local .htaccess authors to read files with the privileges of the httpd user.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-24072)

Heap-based Buffer Overflow vulnerability in mod_proxy_ajp of Apache HTTP Server. If mod_proxy_ajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to mod_proxy_ajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-28780)

Allocation of Resources Without Limits or Throttling vulnerability in Apache HTTP Server's  mod_md via OCSP response data.

This issue affects Apache HTTP Server: from 2.4.30 through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-29168)

A NULL pointer dereference in mod_dav_lock in Apache HTTP Server 2.4.66 and earlier may allow an attacker to crash the server with a malicious request.mod_dav_lock is not used internally by mod_dav or mod_dav_fs.

The only known use-case for mod_dav_lock was mod_dav_svn from Apache Subversion earlier than version 1.2.0.

Users are recommended to upgrade to version 2.4.66, which fixes this issue, or remove mod_dav_lock.(CVE-2026-29169)

A timing attack against mod_auth_digest in Apache HTTP Server 2.4.66 allows a bypass of Digest authentication by a remote attacker.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33006)

A NULL pointer dereference in the mod_authn_socache in Apache HTTP Server 2.4.66 and earlier allows an unauthenticated remote user to crash a child process in a caching forward proxy configuration.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33007)

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33523)

Out-of-bounds Read vulnerability in mod_proxy_ajp of

Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33857)

Buffer Over-read vulnerability in Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-34059)

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

Security Fix(es):

A NULL pointer dereference in the mod_authn_socache in Apache HTTP Server 2.4.66 and earlier allows an unauthenticated remote user to crash a child process in a caching forward proxy configuration.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33007)

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33523)

Out-of-bounds Read vulnerability in mod_proxy_ajp of

Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33857)

Improper Null Termination, Out-of-bounds Read vulnerability in Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-34032)

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

Security Fix(es):

A NULL pointer dereference in the mod_authn_socache in Apache HTTP Server 2.4.66 and earlier allows an unauthenticated remote user to crash a child process in a caching forward proxy configuration.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33007)

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33523)

Out-of-bounds Read vulnerability in mod_proxy_ajp of

Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33857)

Improper Null Termination, Out-of-bounds Read vulnerability in Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-34032)

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

Security Fix(es):

An escalation of privilege bug in various modules in Apache HTTP 2.4.66 and earlier allows local .htaccess authors to read files with the privileges of the httpd user.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-24072)

Allocation of Resources Without Limits or Throttling vulnerability in Apache HTTP Server's  mod_md via OCSP response data.

This issue affects Apache HTTP Server: from 2.4.30 through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-29168)

A NULL pointer dereference in mod_dav_lock in Apache HTTP Server 2.4.66 and earlier may allow an attacker to crash the server with a malicious request.mod_dav_lock is not used internally by mod_dav or mod_dav_fs.

The only known use-case for mod_dav_lock was mod_dav_svn from Apache Subversion earlier than version 1.2.0.

Users are recommended to upgrade to version 2.4.66, which fixes this issue, or remove mod_dav_lock.(CVE-2026-29169)

A timing attack against mod_auth_digest in Apache HTTP Server 2.4.66 allows a bypass of Digest authentication by a remote attacker.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33006)

A NULL pointer dereference in the mod_authn_socache in Apache HTTP Server 2.4.66 and earlier allows an unauthenticated remote user to crash a child process in a caching forward proxy configuration.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33007)

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33523)

Out-of-bounds Read vulnerability in mod_proxy_ajp of

Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33857)

Improper Null Termination, Out-of-bounds Read vulnerability in Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-34032)

Buffer Over-read vulnerability in Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-34059)

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

Security Fix(es):

A NULL pointer dereference in the mod_authn_socache in Apache HTTP Server 2.4.66 and earlier allows an unauthenticated remote user to crash a child process in a caching forward proxy configuration.

Users are recommended to upgrade to version 2.4.67, which fixes this issue.(CVE-2026-33007)

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33523)

Out-of-bounds Read vulnerability in mod_proxy_ajp of

Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-33857)

Improper Null Termination, Out-of-bounds Read vulnerability in Apache HTTP Server.

This issue affects Apache HTTP Server: through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.(CVE-2026-34032)

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers. This issue affects Apache HTTP Server: from through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.

HTTP response splitting vulnerability in multiple Apache HTTP Server modules with untrusted or compromised backend servers.

This issue affects Apache HTTP Server: from through 2.4.66.

Users are recommended to upgrade to version 2.4.67, which fixes the issue.

• CVE-2026-24072: fix mod_rewrite ap_expr privilege escalation in htaccess
• CVE-2026-28780: fix mod_proxy_ajp ajp_msg_check_header buffer over-read
• CVE-2026-29169: fix mod_dav_lock NULL pointer dereference
• CVE-2026-33006: fix mod_auth_digest timing attack
• CVE-2026-33007: fix mod_authn_socache NULL pointer dereference
• CVE-2026-33523: fix HTTP response splitting via status line
• CVE-2026-33857: fix off-by-one OOB reads in AJP getter functions
• CVE-2026-34032: fix ajp_msg_get_string buffer over-read
• CVE-2026-34059: fix ajp_parse_data heap over-read

• CVE-2026-24072: fix mod_rewrite ap_expr privilege escalation in htaccess
• CVE-2026-28780: fix mod_proxy_ajp ajp_msg_check_header buffer over-read
• CVE-2026-29169: fix mod_dav_lock NULL pointer dereference
• CVE-2026-33006: fix mod_auth_digest timing attack
• CVE-2026-33007: fix mod_authn_socache NULL pointer dereference
• CVE-2026-33523: fix HTTP response splitting via status line
• CVE-2026-33857: fix off-by-one OOB reads in AJP getter functions
• CVE-2026-34032: fix ajp_msg_get_string buffer over-read
• CVE-2026-34059: fix ajp_parse_data heap over-read

• CVE-2026-24072: mod_rewrite/mod_setenvif: use AP_EXPR_FLAG_RESTRICTED in htaccess to prevent reading server-side files via ap_expr from .htaccess
• CVE-2026-29169: mod_dav_lock: NULL pointer dereference in dav_generic_refresh_locks (use dp_scan instead of dp)
• CVE-2026-33006: mod_auth_digest: timing attack — use constant-time compare for nonce/digest verification
• CVE-2026-33007: mod_authn_socache: NULL pointer dereference when r->uri has no '/' in directory context
• CVE-2026-33523: scan outgoing status line for newlines and control characters to prevent HTTP response splitting
• CVE-2026-33857: mod_proxy_ajp: off-by-one OOB reads in ajp_msg_get/peek length checks
• CVE-2026-34032: mod_proxy_ajp: improper null termination and OOB read in ajp_msg_get_string
• CVE-2026-34059: mod_proxy_ajp: heap over-read in ajp_parse_data when message is too small

• CVE-2026-24072: mod_rewrite/mod_setenvif: use AP_EXPR_FLAG_RESTRICTED in htaccess to prevent reading server-side files via ap_expr from .htaccess
• CVE-2026-29169: mod_dav_lock: NULL pointer dereference in dav_generic_refresh_locks (use dp_scan instead of dp)
• CVE-2026-33006: mod_auth_digest: timing attack — use constant-time compare for nonce/digest verification
• CVE-2026-33007: mod_authn_socache: NULL pointer dereference when r->uri has no '/' in directory context
• CVE-2026-33523: scan outgoing status line for newlines and control characters to prevent HTTP response splitting
• CVE-2026-33857: mod_proxy_ajp: off-by-one OOB reads in ajp_msg_get/peek length checks
• CVE-2026-34032: mod_proxy_ajp: improper null termination and OOB read in ajp_msg_get_string
• CVE-2026-34059: mod_proxy_ajp: heap over-read in ajp_parse_data when message is too small

• CVE-2026-33857: fix length checks in AJP msg_get functions
• CVE-2026-34032: fix ajp_msg_get_string buffer checks
• CVE-2026-34059: fix ajp_parse_data message len check
• CVE-2026-24072: use AP_EXPR_FLAG_RESTRICTED in htaccess
• CVE-2026-29169: mod_dav_lock: use the right dav_lock_discovery
• CVE-2026-33006: mod_auth_digest: use apr_crypto_equals
• CVE-2026-33007: mod_authn_socache: validate URL earlier
• CVE-2026-33523: scan outgoing status line for newlines and controls
• CVE-2026-28780: fix ajp_msg_check_header check

• CVE-2026-24072: use AP_EXPR_FLAG_RESTRICTED in htaccess
• CVE-2026-29169: mod_dav_lock: use the right dav_lock_discovery
• CVE-2026-33006: mod_auth_digest: use apr_crypto_equals
• CVE-2026-33007: mod_authn_socache: validate URL earlier
• CVE-2026-33523: scan outgoing status line for newlines and controls
• CVE-2026-33857: fix length checks in AJP msg_get functions
• CVE-2026-34032: fix ajp_msg_get_string buffer checks
• CVE-2026-34059: fix ajp_parse_data message len check

• CVE-2026-24072: fix mod_rewrite ap_expr privilege escalation in htaccess
• CVE-2026-28780: fix mod_proxy_ajp ajp_msg_check_header buffer over-read
• CVE-2026-29169: fix mod_dav_lock NULL pointer dereference
• CVE-2026-33006: fix mod_auth_digest timing attack
• CVE-2026-33007: fix mod_authn_socache NULL pointer dereference
• CVE-2026-33523: fix HTTP response splitting via status line
• CVE-2026-33857: fix off-by-one OOB reads in AJP getter functions
• CVE-2026-34032: fix ajp_msg_get_string buffer over-read
• CVE-2026-34059: fix ajp_parse_data heap over-read

• SECURITY UPDATE: off-by-one OOB read in mod_proxy_ajp message getters
  • debian/patches/CVE-2026-33857.patch: tighten length checks (> msg->len -> >= msg->len) in ajp_msg_get_uint8/16/32 and ajp_msg_peek_uint8/16 in modules/proxy/ajp_msg.c.
  • CVE-2026-33857
• SECURITY UPDATE: heap over-read in mod_proxy_ajp via missing null-termination check in ajp_msg_get_string()
  • debian/patches/CVE-2026-34032.patch: switch the buffer overflow check to compare against msg->len and verify the expected null terminator is present before returning the pointer in modules/proxy/ajp_msg.c.
  • CVE-2026-34032
• SECURITY UPDATE: heap over-read and memory disclosure in mod_proxy_ajp ajp_parse_data() via missing minimum message-length validation
  • debian/patches/CVE-2026-34059.patch: reject AJP data messages whose msg->len is smaller than AJP_HEADER_LEN + AJP_HEADER_SZ_LEN + 1 + 1 before computing expected_len in modules/proxy/ajp_header.c.
  • CVE-2026-34059
• SECURITY UPDATE: local information disclosure via .htaccess / mod_setenvif / ProxyFCGISetEnvIf, where a non-privileged user with .htaccess write access could read files accessible to the httpd service account
  • debian/patches/CVE-2026-24072.patch: pass AP_EXPR_FLAG_RESTRICTED when parsing ap_expr expressions from htaccess context in modules/mappers/mod_rewrite.c, modules/metadata/mod_setenvif.c, and modules/proxy/mod_proxy_fcgi.c.
  • CVE-2026-24072
• SECURITY UPDATE: timing attack against mod_auth_digest allowing bypass of Digest authentication
  • debian/patches/CVE-2026-33006.patch: validate nonce and digest lengths earlier and replace the strcmp of the nonce hash with the constant-time apr_crypto_equals (apr-util >= 1.6) in modules/aaa/mod_auth_digest.c; bump APU minimum to 1.6 in configure.in.
  • CVE-2026-33006
• SECURITY UPDATE: NULL pointer dereference in mod_authn_socache crashes the child process in a caching forward proxy setup
  • debian/patches/CVE-2026-33007.patch: validate the URL before using the cache hash in construct_key() in modules/aaa/mod_authn_socache.c.
  • CVE-2026-33007
• SECURITY UPDATE: HTTP response splitting via newline/control characters in an outgoing status line forwarded from a compromised backend
  • debian/patches/CVE-2026-33523.patch: reject status reason strings that contain newlines or control characters in modules/http/http_filters.c.
  • CVE-2026-33523

• CVE-2026-24072: mod_rewrite/mod_setenvif: use AP_EXPR_FLAG_RESTRICTED in htaccess to prevent reading server-side files via ap_expr from .htaccess
• CVE-2026-29169: mod_dav_lock: NULL pointer dereference in dav_generic_refresh_locks (use dp_scan instead of dp)
• CVE-2026-33006: mod_auth_digest: timing attack — use constant-time compare for nonce/digest verification
• CVE-2026-33007: mod_authn_socache: NULL pointer dereference when r->uri has no '/' in directory context
• CVE-2026-33523: scan outgoing status line for newlines and control characters to prevent HTTP response splitting
• CVE-2026-33857: mod_proxy_ajp: off-by-one OOB reads in ajp_msg_get/peek length checks
• CVE-2026-34032: mod_proxy_ajp: improper null termination and OOB read in ajp_msg_get_string
• CVE-2026-34059: mod_proxy_ajp: heap over-read in ajp_parse_data when message is too small

• SECURITY UPDATE: mod_proxy_ajp heap buffer over-read in ajp_msg_get_string
  • debian/patches/CVE-2026-34032.patch: add buffer checks in modules/proxy/ajp_msg.c.
  • CVE-2026-34032
• SECURITY UPDATE: AJP getter functions off-by-one out-of-bounds reads
  • debian/patches/CVE-2026-33857.patch: fix length checks in AJP msg_get functions in modules/proxy/ajp_msg.c.
  • CVE-2026-33857
• SECURITY UPDATE: mod_proxy_ajp heap over-read in ajp_parse_data
  • debian/patches/CVE-2026-34059.patch: fix message length check in modules/proxy/ajp_header.c.
  • CVE-2026-34059
• SECURITY UPDATE: mod_authn_socache crash in caching forward proxy
  • debian/patches/CVE-2026-33007.patch: validate URL earlier in modules/aaa/mod_authn_socache.c.
  • CVE-2026-33007
• SECURITY UPDATE: HTTP response splitting via malicious backend status line
  • debian/patches/CVE-2026-33523.patch: scan outgoing status line for newlines and controls in modules/http/http_filters.c.
  • CVE-2026-33523
• SECURITY UPDATE: mod_rewrite elevation of privileges via ap_expr in .htaccess
  • debian/patches/CVE-2026-24072.patch: use AP_EXPR_FLAG_RESTRICTED in htaccess context in modules/mappers/mod_rewrite.c, modules/metadata/mod_setenvif.c, modules/proxy/mod_proxy_fcgi.c.
  • CVE-2026-24072
• SECURITY UPDATE: mod_auth_digest timing attack allowing Digest auth bypass
  • debian/patches/CVE-2026-33006.patch: use apr_crypto_equals (constant- time comparison) for nonce hash and digest checks, add VALID_NONCE validation and MD5_DIGEST_LEN length check in get_digest_rec, in modules/aaa/mod_auth_digest.c. Bumps configure.in apr-util requirement to >= 1.6 (bionic ships 1.6.1).
  • CVE-2026-33006
• SECURITY UPDATE: mod_proxy_ajp ajp_msg_check_header bounds-check fix
  • debian/patches/CVE-2026-28780.patch: tighten the upper-bound check in ajp_msg_check_header() to reserve AJP_HEADER_LEN bytes of headroom in modules/proxy/ajp_msg.c (companion to CVE-2026-33857/34032).
  • CVE-2026-28780

• SECURITY UPDATE: fix off-by-one out-of-bounds read in mod_proxy_ajp message getter functions
  • debian/patches/CVE-2026-33857-prereq.patch: prerequisite fix for ajp_msg_check_header bounds check to keep msg->len within buffer
  • debian/patches/CVE-2026-33857.patch: fix off-by-one out-of-bounds read in mod_proxy_ajp message getter functions
  • CVE-2026-33857
• SECURITY UPDATE: fix improper null termination and out-of-bounds read in ajp_msg_get_string
  • debian/patches/CVE-2026-34032.patch: fix improper null termination and out-of-bounds read in ajp_msg_get_string
  • CVE-2026-34032
• SECURITY UPDATE: fix heap buffer over-read in mod_proxy_ajp ajp_parse_data
  • debian/patches/CVE-2026-34059.patch: fix heap buffer over-read in mod_proxy_ajp ajp_parse_data
  • CVE-2026-34059
• SECURITY UPDATE: use restricted ap_expr parser in htaccess context to prevent local privilege escalation
  • debian/patches/CVE-2026-24072.patch: use restricted ap_expr parser in htaccess context to prevent local privilege escalation
  • CVE-2026-24072
• SECURITY UPDATE: fix NULL pointer dereference crash in mod_dav_lock dav_generic_refresh_locks
  • debian/patches/CVE-2026-29169.patch: fix NULL pointer dereference crash in mod_dav_lock dav_generic_refresh_locks
  • CVE-2026-29169
• SECURITY UPDATE: fix timing attack allowing Digest authentication bypass in mod_auth_digest
  • debian/patches/CVE-2026-33006.patch: fix timing attack allowing Digest authentication bypass in mod_auth_digest
  • CVE-2026-33006
• SECURITY UPDATE: fix NULL pointer dereference crash in mod_authn_socache
  • debian/patches/CVE-2026-33007.patch: fix NULL pointer dereference crash in mod_authn_socache
  • CVE-2026-33007
• SECURITY UPDATE: fix HTTP response splitting via newlines/controls in outgoing status line
  • debian/patches/CVE-2026-33523.patch: fix HTTP response splitting via newlines/controls in outgoing status line
  • CVE-2026-33523

• SECURITY UPDATE: mod_proxy_ajp heap buffer over-read in ajp_msg_get_string
  • debian/patches/CVE-2026-34032.patch: add buffer checks in modules/proxy/ajp_msg.c.
  • CVE-2026-34032
• SECURITY UPDATE: AJP getter functions off-by-one out-of-bounds reads
  • debian/patches/CVE-2026-33857.patch: fix length checks in AJP msg_get functions in modules/proxy/ajp_msg.c.
  • CVE-2026-33857
• SECURITY UPDATE: mod_proxy_ajp heap over-read in ajp_parse_data
  • debian/patches/CVE-2026-34059.patch: fix message length check in modules/proxy/ajp_header.c.
  • CVE-2026-34059
• SECURITY UPDATE: mod_authn_socache crash in caching forward proxy
  • debian/patches/CVE-2026-33007.patch: validate URL earlier in modules/aaa/mod_authn_socache.c.
  • CVE-2026-33007
• SECURITY UPDATE: HTTP response splitting via malicious backend status line
  • debian/patches/CVE-2026-33523.patch: scan outgoing status line for newlines and controls in modules/http/http_filters.c.
  • CVE-2026-33523
• SECURITY UPDATE: mod_rewrite elevation of privileges via ap_expr in .htaccess
  • debian/patches/CVE-2026-24072.patch: use AP_EXPR_FLAG_RESTRICTED in htaccess context in modules/mappers/mod_rewrite.c and modules/metadata/mod_setenvif.c. mod_proxy_fcgi hunk omitted — ProxyFCGISetEnvIf was added in 2.4.26, after this source.
  • CVE-2026-24072
• SECURITY UPDATE: mod_auth_digest timing attack allowing Digest auth bypass
  • debian/patches/CVE-2026-33006.patch: use a constant-time comparison helper for nonce hash and digest checks, add VALID_NONCE validation and MD5_DIGEST_LEN length check in get_digest_rec, in modules/aaa/mod_auth_digest.c. Inline ap_crypto_equals_const_time() replaces apr_crypto_equals (added in apr-util 1.6, not in xenial's apr-util 1.5.4); the upstream apr-util version bump and the apr_crypto.h include are omitted accordingly.
  • CVE-2026-33006
• SECURITY UPDATE: mod_proxy_ajp ajp_msg_check_header bounds-check fix
  • debian/patches/CVE-2026-28780.patch: tighten the upper-bound check in ajp_msg_check_header() to reserve AJP_HEADER_LEN bytes of headroom in modules/proxy/ajp_msg.c (companion to CVE-2026-33857/34032).
  • CVE-2026-28780

http2: double free and possible RCE on early reset. (CVE-2026-23918) mod_rewrite elevation of privileges via ap_expr. (CVE-2026-24072) buffer overflow in mod_proxy_ajp via ajp_msg_check_header(). (CVE-2026-28780) mod_md unrestricted OCSP response. (CVE-2026-29168) mod_dav_lock indirect lock crash. (CVE-2026-29169) mod_auth_digest timing attack. (CVE-2026-33006) mod_authn_socache crash. (CVE-2026-33007) HTTP response splitting forwarding malicious status line. (CVE-2026-33523) Off-by-one OOB reads in AJP getter functions. (CVE-2026-33857) Heap Buffer Over-Read Due to Missing Null-Termination Check (ajp_msg_get_string). (CVE-2026-34032) Heap Over-Read and memory disclosure in ajp_parse_data(). (CVE-2026-34059)

These are all security issues fixed in the apache2-2.4.67-1.1 package on the GA media of openSUSE Tumbleweed.

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).

This update for apache2 fixes the following issues

Update to 2.4.66 (jsc#PED-16334):

Security issues:

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).

Non security issue:

• Internal server error on very long URL (bsc#690734).

This update for apache2 fixes the following issues

• CVE-2026-23918: http2: double free and possible RCE on early reset (bsc#1263957).
• CVE-2026-24072: mod_rewrite elevation of privileges via ap_expr (bsc#1263935).
• CVE-2026-28780: heap buffer overflow in mod_proxy_ajp via ajp_msg_check_header() (bsc#1264163).
• CVE-2026-29167: mod_ldap per-dir use-after-free (bsc#1267976).
• CVE-2026-29168: allocation of resources without limits in mod_md via OCSP response (bsc#1264150).
• CVE-2026-29169: NULL pointer dereference in mod_dav_lock allows server crash via malicious requests (bsc#1263956).
• CVE-2026-29170: mod_proxy_ftp XSS (bsc#1267977).
• CVE-2026-33006: mod_auth_digest timing attack allows bypass of Digest authentication (bsc#1263955).
• CVE-2026-33007: NULL pointer dereference in mod_authn_socache allows unauthenticated remote user to crash a child processes (bsc#1263954).
• CVE-2026-33523: HTTP response splitting forwarding malicious status line (bsc#1263953).
• CVE-2026-33857: off-by-one OOB reads in AJP getter functions (bsc#1263952).
• CVE-2026-34032: heap buffer overread in mod_proxy_ajp due to missing null-termination check (bsc#1263951).
• CVE-2026-34059: heap buffer overread and memory disclosure via ajp_parse_data() (bsc#1263950).
• CVE-2026-34355: mod_proxy_html buffer overflow (bsc#1267978).
• CVE-2026-34356: malicious backend servers can lead to a heap-based buffer overflow (bsc#1267955).
• CVE-2026-42535: malicious path manipulation can lead to child process crashes (bsc#1267956).
• CVE-2026-42536: processing untrusted content can lead to a heap-based buffer overflow (bsc#1267962).
• CVE-2026-43951: out-of-bound read in merge_response_headers can cause crash (bsc#1267963).
• CVE-2026-44119: improper privilege management can lead to an unauthorized read (bsc#1267965).
• CVE-2026-44185: Stack Buffer Over-Read in mod_ssl OCSP send_request (bsc#1267969).
• CVE-2026-44186: responses from an attacker-controlled FTP backend can lead to resource exhaustion and a denial of service (bsc#1267970).
• CVE-2026-44631: crafted regular expression can lead to a buffer underwrite (bsc#1267971).
• CVE-2026-48913: file handle exhaustion during request processing in mod_http2 can lead to a use-after-free (bsc#1267972).
• CVE-2026-49975: Fix cookie header accounting against LimitRequestFields (bsc#1267503).

Non security issue:

• Update to 2.4.66 (jsc#PED-16334).

Pavel Kohout and Arkadi Vainbrand discovered that Apache HTTP Server incorrectly handled certain memory operations in mod_authn_socache. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-33007)

Haruki Oyama, Merih Mengisteab, and Dawit Jeong discovered that Apache HTTP Server had an HTTP response splitting vulnerability in multiple modules when used with untrusted or compromised backend servers. An attacker could possibly use this issue to inject arbitrary HTTP headers. (CVE-2026-33523)

Elhanan Haenel discovered that Apache HTTP Server incorrectly handled certain memory operations in mod_proxy_ajp. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-33857)

Tianshuo Han and Jérôme Djouder discovered that Apache HTTP Server incorrectly handled certain string operations in mod_proxy_ajp. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-34032)

It was discovered that Apache HTTP Server's mod_proxy_html module incorrectly handled certain content from an untrusted backend. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-34355)

It was discovered that Apache HTTP Server incorrectly handled ProxyPassReverseCookie directives with a malicious backend server. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-34356)

It was discovered that Apache HTTP Server's mod_dav_fs module incorrectly handled certain path operations. An authenticated user could possibly use this issue to manipulate trusted WebDAV property databases or cause a denial of service. (CVE-2026-42535)

It was discovered that Apache HTTP Server's mod_xml2enc module incorrectly handled certain content from an untrusted backend. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-42536)

It was discovered that Apache HTTP Server incorrectly handled response headers when multiple content languages were configured. A remote attacker could possibly use this issue to obtain sensitive information. (CVE-2026-43951)

It was discovered that Apache HTTP Server incorrectly restricted certain file functions in expressions within .htaccess files. A local attacker with .htaccess write access could possibly use this issue to obtain sensitive information. (CVE-2026-44119)

It was discovered that Apache HTTP Server's mod_ssl module incorrectly handled OCSP responses from an attacker-controlled server. A remote attacker could possibly use this issue to obtain sensitive information or cause a denial of service. (CVE-2026-44185)

It was discovered that Apache HTTP Server's mod_proxy_ftp module incorrectly handled responses from an attacker-controlled backend FTP server. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-44186)

It was discovered that Apache HTTP Server incorrectly handled crafted regular expressions in the server configuration. An attacker could possibly use this issue to execute arbitrary code or cause a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-44631)

It was discovered that Apache HTTP Server's mod_http2 module had a use-after-free vulnerability when file handles were exhausted. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-48913)