CVE-2025-49812

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade. Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

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

Security Fix(es):

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.(CVE-2024-42516)

SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.  Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request.

Users are recommended to upgrade to version 2.4.64 which fixes this issue.(CVE-2024-43204)

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.(CVE-2024-47252)

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption.

Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.(CVE-2025-23048)

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.(CVE-2025-49812)

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

Security Fix(es):

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.(CVE-2024-42516)

SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.  Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request.

Users are recommended to upgrade to version 2.4.64 which fixes this issue.(CVE-2024-43204)

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.(CVE-2024-47252)

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption.

Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.(CVE-2025-23048)

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.(CVE-2025-49812)

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

Security Fix(es):

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.(CVE-2024-42516)

SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.  Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request.

Users are recommended to upgrade to version 2.4.64 which fixes this issue.(CVE-2024-43204)

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.(CVE-2024-47252)

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption.

Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.(CVE-2025-23048)

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.(CVE-2025-49812)

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

Security Fix(es):

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.(CVE-2024-42516)

SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.  Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request.

Users are recommended to upgrade to version 2.4.64 which fixes this issue.(CVE-2024-43204)

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.(CVE-2024-47252)

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption.

Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.(CVE-2025-23048)

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.(CVE-2025-49812)

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

Security Fix(es):

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.(CVE-2024-42516)

SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.  Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request.

Users are recommended to upgrade to version 2.4.64 which fixes this issue.(CVE-2024-43204)

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.(CVE-2024-47252)

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption.

Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.(CVE-2025-23048)

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.(CVE-2025-49812)

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

Security Fix(es):

HTTP response splitting in the core of Apache HTTP Server allows an attacker who can manipulate the Content-Type response headers of applications hosted or proxied by the server can split the HTTP response.

This vulnerability was described as CVE-2023-38709 but the patch included in Apache HTTP Server 2.4.59 did not address the issue.

Users are recommended to upgrade to version 2.4.64, which fixes this issue.(CVE-2024-42516)

SSRF in Apache HTTP Server with mod_proxy loaded allows an attacker to send outbound proxy requests to a URL controlled by the attacker.  Requires an unlikely configuration where mod_headers is configured to modify the Content-Type request or response header with a value provided in the HTTP request.

Users are recommended to upgrade to version 2.4.64 which fixes this issue.(CVE-2024-43204)

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided by the client may appear in log files.(CVE-2024-47252)

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption.

Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.(CVE-2025-23048)

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.(CVE-2025-49812)

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

Security Fix(es):

• httpd: insufficient escaping of user-supplied data in mod_ssl (CVE-2024-47252)

• httpd: mod_ssl: access control bypass by trusted clients is possible using TLS 1.3 session resumption (CVE-2025-23048)

• httpd: HTTP Session Hijack via a TLS upgrade (CVE-2025-49812)

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: insufficient escaping of user-supplied data in mod_ssl (CVE-2024-47252)

• httpd: mod_ssl: access control bypass by trusted clients is possible using TLS 1.3 session resumption (CVE-2025-23048)

• httpd: HTTP Session Hijack via a TLS upgrade (CVE-2025-49812)

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: insufficient escaping of user-supplied data in mod_ssl (CVE-2024-47252)

• httpd: mod_ssl: access control bypass by trusted clients is possible using TLS 1.3 session resumption (CVE-2025-23048)

• httpd: mod_proxy_http2: untrusted input from a client causes an assertion to fail in the Apache mod_proxy_http2 module (CVE-2025-49630)

• httpd: HTTP Session Hijack via a TLS upgrade (CVE-2025-49812)

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.

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade. Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

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

Security Fix(es):

• httpd: insufficient escaping of user-supplied data in mod_ssl (CVE-2024-47252)
• httpd: mod_ssl: access control bypass by trusted clients is possible using TLS 1.3 session resumption (CVE-2025-23048)
• httpd: HTTP Session Hijack via a TLS upgrade (CVE-2025-49812)

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: insufficient escaping of user-supplied data in mod_ssl (CVE-2024-47252)
• httpd: mod_ssl: access control bypass by trusted clients is possible using TLS 1.3 session resumption (CVE-2025-23048)
• httpd: HTTP Session Hijack via a TLS upgrade (CVE-2025-49812)

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: insufficient escaping of user-supplied data in mod_ssl (CVE-2024-47252)
• httpd: mod_ssl: access control bypass by trusted clients is possible using TLS 1.3 session resumption (CVE-2025-23048)
• httpd: mod_proxy_http2: untrusted input from a client causes an assertion to fail in the Apache mod_proxy_http2 module (CVE-2025-49630)
• httpd: HTTP Session Hijack via a TLS upgrade (CVE-2025-49812)

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.

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.

Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

• SECURITY UPDATE: mod_ssl TLS upgrade attack
  • debian/patches/CVE-2025-49812.patch: remove antiquated 'SSLEngine optional' TLS upgrade in modules/ssl/ssl_engine_config.c, modules/ssl/ssl_engine_init.c, modules/ssl/ssl_engine_kernel.c, modules/ssl/ssl_private.h.
  • CVE-2025-49812

• SECURITY UPDATE: mod_ssl TLS upgrade attack
  • debian/patches/CVE-2025-49812.patch: remove antiquated 'SSLEngine optional' TLS upgrade in modules/ssl/ssl_engine_config.c, modules/ssl/ssl_engine_init.c, modules/ssl/ssl_engine_kernel.c, modules/ssl/ssl_private.h.
  • CVE-2025-49812

• CVE-2025-49812: remove support for TLS upgrade to prevent HTTP desynchronisation attacks in mod_ssl configurations

• CVE-2024-47252: escape user-supplied data in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log files
• CVE-2025-49812: remove support for TLS upgrade to prevent HTTP desynchronisation attack

• CVE-2024-47252: escape characters are now properly handled in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log files
• CVE-2025-49812: remove support for TLS upgrade to mitigate HTTP desynchronisation attack

• CVE-2024-47252: escape user-supplied data in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log files
• CVE-2025-49812: remove support for TLS upgrade to prevent HTTP desynchronisation attack

• CVE-2024-47252: escape user-supplied data in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log files
• CVE-2025-49812: remove support for TLS upgrade to prevent HTTP desynchronisation attack

• CVE-2024-47252: escape characters are now properly handled in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log files
• CVE-2025-49812: remove support for TLS upgrade to mitigate HTTP desynchronisation attack

• CVE-2025-49630: fix denial of service attack triggered by untrusted clients causing an assertion in mod_proxy_http2
• CVE-2025-23048: fix access control bypass by trusted clients in mod_ssl configurations
• CVE-2024-47252: escape user-supplied data in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log file
• CVE-2025-49812: remove support for TLS upgrade to mitigate HTTP desynchronisation attack

• CVE-2025-49630: fix assertion caused by untrusted clients triggering denial of service attack in mod_proxy_http2
• CVE-2025-23048: fix access control bypass by trusted clients using TLS 1.3 session resumption
• CVE-2024-47252: escape user-supplied data to prevent log file injection in mod_ssl
• CVE-2025-49812: remove support for TLS upgrade to prevent HTTP desynchronisation attack

• CVE-2025-49630: fix denial of service attack triggered by untrusted clients causing an assertion in mod_proxy_http2
• CVE-2025-23048: fix access control bypass by trusted clients in mod_ssl configurations
• CVE-2025-49812: remove support for TLS upgrade to mitigate HTTP desynchronisation attack
• CVE-2024-47252: escape user-supplied data in mod_ssl to prevent untrusted SSL/TLS clients from inserting escape characters into log files

• SECURITY UPDATE: query string passed to SSI "#exec cmd" via mod_cgid
  • debian/patches/CVE-2025-58098.patch: in cgid_server() in modules/generators/mod_cgid.c, do not pass the request query string (r->args) to create_argv() for Server Side Includes requests by passing NULL when cgid_req.req_type == SSI_REQ, and add a NULL guard to create_argv() so a shell-escaped query string can no longer be split into extra arguments of an SSI "#exec cmd" command. Backported from httpd commit ecc1b8f3817e3dcab9c1f24f905752d3c0a279af (SVN r1930161).
  • CVE-2025-58098
• SECURITY UPDATE: log injection via unescaped mod_ssl log variables
  • debian/patches/CVE-2024-47252.patch: in ssl_var_log_handler_c() and ssl_var_log_handler_x() in modules/ssl/ssl_engine_vars.c, escape the SSL/TLS variables returned by these mod_ssl log handlers with ap_escape_logitem() so client-supplied values such as SSL_TLS_SNI logged via "%{varname}c"/"%{varname}x" can no longer insert escape characters into log files. Backported from httpd commit c01e60707048be14a510f0a92128a5227923215c (SVN r1927042).
  • CVE-2024-47252

• rebase to 2.4.6-99.0.9.el7_9.1
• replace the TuxCare backports for CVE-2024-47252, CVE-2025-49812 and CVE-2025-58098 (Patch326-328) with the vendor's own patches (Patch400-402), which carry the identical upstream changes
• all other TuxCare CVE patches are unchanged: Patch300-330 and Patch1000-1014 remain declared and applied

• rebase to 2.4.6-99.0.9.el7_9.1
• replace the TuxCare backports for CVE-2024-47252, CVE-2025-49812 and CVE-2025-58098 (Patch326-328) with the vendor's own patches (Patch400-402), which carry the identical upstream changes
• all other TuxCare CVE patches are unchanged: Patch300-330 and Patch1000-1014 remain declared and applied

• rebase to 2.4.6-99.0.9.el7_9.1
• replace the TuxCare backports for CVE-2024-47252, CVE-2025-49812 and CVE-2025-58098 (Patch326-328) with the vendor's own patches (Patch400-402), which carry the identical upstream changes
• all other TuxCare CVE patches are unchanged: Patch300-330 and Patch1000-1014 remain declared and applied