Apache: >> Http Server >> 2.4.26 Security Vulnerabilities
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.
CVSS Score
9.8
EPSS Score
0.016
Published
2026-05-05
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.
CVSS Score
7.5
EPSS Score
0.006
Published
2026-05-04
Apache HTTP Server 2.4.65 and earlier with Server Side Includes (SSI) enabled and mod_cgid (but not mod_cgi) passes the shell-escaped query string to #exec cmd="..." directives.
This issue affects Apache HTTP Server before 2.4.66.
Users are recommended to upgrade to version 2.4.66, which fixes the issue.
CVSS Score
8.3
EPSS Score
0.014
Published
2025-12-05
Server-Side Request Forgery (SSRF) vulnerability
in Apache HTTP Server on Windows
with AllowEncodedSlashes On and MergeSlashes Off allows to potentially leak NTLM
hashes to a malicious server via SSRF and malicious requests or content
Users are recommended to upgrade to version 2.4.66, which fixes the issue.
CVSS Score
7.5
EPSS Score
0.008
Published
2025-12-05
Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache HTTP Server through environment variables set via the Apache configuration unexpectedly superseding variables calculated by the server for CGI programs.
This issue affects Apache HTTP Server from 2.4.0 through 2.4.65.
Users are recommended to upgrade to version 2.4.66 which fixes the issue.
CVSS Score
6.5
EPSS Score
0.008
Published
2025-12-05
mod_userdir+suexec bypass via AllowOverride FileInfo vulnerability in Apache HTTP Server. Users with access to use the RequestHeader directive in htaccess can cause some CGI scripts to run under an unexpected userid.
This issue affects Apache HTTP Server: from 2.4.7 through 2.4.65.
Users are recommended to upgrade to version 2.4.66, which fixes the issue.
CVSS Score
5.4
EPSS Score
0.006
Published
2025-12-05
In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.63 can be triggered by untrusted clients causing an assertion in mod_proxy_http2.
Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to "on".
CVSS Score
7.5
EPSS Score
0.014
Published
2025-07-10
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.
CVSS Score
7.4
EPSS Score
0.006
Published
2025-07-10
Late Release of Memory after Effective Lifetime vulnerability in Apache HTTP Server.
This issue affects Apache HTTP Server: from 2.4.17 up to 2.4.63.
Users are recommended to upgrade to version 2.4.64, which fixes the issue.
CVSS Score
7.5
EPSS Score
0.05
Published
2025-07-10
Server-Side Request Forgery (SSRF) in Apache HTTP Server on Windows allows to potentially leak NTLM hashes to a malicious server via
mod_rewrite or apache expressions that pass unvalidated request input.
This issue affects Apache HTTP Server: from 2.4.0 through 2.4.63.
Note: The Apache HTTP Server Project will be setting a higher bar for accepting vulnerability reports regarding SSRF via UNC paths.
The server offers limited protection against administrators directing the server to open UNC paths.
Windows servers should limit the hosts they will connect over via SMB based on the nature of NTLM authentication.
CVSS Score
7.5
EPSS Score
0.013
Published
2025-07-10