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.
Problem types
CWE-476 NULL Pointer Dereference
Product status
Any version
Timeline
| 2026-03-04: | Report received |
| 2026-05-04: | 2.4.67 released |
| 2026-05-04: | fixed in 2.4.x by r1933354 |
Credits
Pavel Kohout, Aisle Research, Aisle.com
References
www.openwall.com/lists/oss-security/2026/05/04/20
www.openwall.com/lists/oss-security/2026/05/05/12
httpd.apache.org/security/vulnerabilities_24.html