Apache: >> Http Server >> 2.4.33 Security Vulnerabilities
Use After Free vulnerability in Apache HTTP Server with mod_ldap in per-directory configuration
This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67.
Users are recommended to upgrade to version 2.4.68, which fixes the issue.
CVSS Score
9.8
EPSS Score
0.007
Published
2026-06-08
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
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.
CVSS Score
7.3
EPSS Score
0.006
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
An integer overflow in the case of failed ACME certificate renewal leads, after a number of failures (~30 days in default configurations), to the backoff timer becoming 0. Attempts to renew the certificate then are repeated without delays until it succeeds.
This issue affects Apache HTTP Server: from 2.4.30 before 2.4.66.
Users are recommended to upgrade to version 2.4.66, which fixes the issue.
CVSS Score
7.5
EPSS Score
0.004
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