Apache HTTP Server up to 2.4.66 mod_dav_lock/mod_dav_svn null pointer dereference

Summaryinfo

A vulnerability was found in Apache HTTP Server up to 2.4.66. It has been rated as problematic. This issue affects some unknown processing of the component mod_dav_lock/mod_dav_svn. Performing a manipulation results in null pointer dereference. This vulnerability is cataloged as CVE-2026-29169. It is possible to initiate the attack remotely. There is no exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Apache HTTP Server up to 2.4.66. It has been classified as problematic. This affects an unknown function of the component mod_dav_lock/mod_dav_svn. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. The summary by CVE is:

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.

The weakness was shared by Pavel Kohout. The advisory is shared at httpd.apache.org. This vulnerability is uniquely identified as CVE-2026-29169 since 03/04/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 05/13/2026).

The vulnerability scanner Nessus provides a plugin with the ID 312237 (Linux Distros Unpatched Vulnerability : CVE-2026-29169), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.67 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (312237), EUVD (EUVD-2026-26957) and CERT Bund (WID-SEC-2026-1354). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Debian Linux
• Red Hat Enterprise Linux
• Fedora Linux
• Ubuntu Linux
• IBM HTTP Server
• Microsoft Azure Linux
• Apache HTTP Server

Productinfo

Type

• Web Server

Vendor

• Apache

Name

• HTTP Server

Version

• 2.4.0
• 2.4.1
• 2.4.2
• 2.4.3
• 2.4.4
• 2.4.5
• 2.4.6
• 2.4.7
• 2.4.8
• 2.4.9
• 2.4.10
• 2.4.11
• 2.4.12
• 2.4.13
• 2.4.14
• 2.4.15
• 2.4.16
• 2.4.17
• 2.4.18
• 2.4.19
• 2.4.20
• 2.4.21
• 2.4.22
• 2.4.23
• 2.4.24
• 2.4.25
• 2.4.26
• 2.4.27
• 2.4.28
• 2.4.29
• 2.4.30
• 2.4.31
• 2.4.32
• 2.4.33
• 2.4.34
• 2.4.35
• 2.4.36
• 2.4.37
• 2.4.38
• 2.4.39
• 2.4.40
• 2.4.41
• 2.4.42
• 2.4.43
• 2.4.44
• 2.4.45
• 2.4.46
• 2.4.47
• 2.4.48
• 2.4.49
• 2.4.50
• 2.4.51
• 2.4.52
• 2.4.53
• 2.4.54
• 2.4.55
• 2.4.56
• 2.4.57
• 2.4.58
• 2.4.59
• 2.4.60
• 2.4.61
• 2.4.62
• 2.4.63
• 2.4.64
• 2.4.65
• 2.4.66

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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