CVE-2026-29169: Apache HTTP Server: mod_dav_lock indirect lock crash

Severity: low 

Affected versions:

- Apache HTTP Server through 2.4.66

Description:

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.

Credit:

Pavel Kohout, Aisle Research, Aisle.com (finder)

References:

https://httpd.apache.org/security/vulnerabilities_24.html
https://httpd.apache.org/
https://www.cve.org/CVERecord?id=CVE-2026-29169

Timeline:

2026-03-04: Report received
2026-05-04: 2.4.67 released
2026-05-04: fixed in 2.4.x by r1933354