CVE-2026-29169Network attack vector

Remote crash via mod_dav_lock NULL dereference

Published May 4, 2026 · Updated May 4, 2026

NULL pointer dereference in mod_dav_lock in Apache HTTP Server 2.4.66 and earlier allows remote attackers to crash the server via a malicious request. The module dereferences a null pointer while processing the crafted DAV request, but Apache has not identified the request field or function involved. Reachability requires mod_dav_lock plus a backend provider that uses it; Apache identifies only mod_dav_svn from Subversion earlier than 1.2.0.

CVSS severity7.5
High
EPSS probability0.59%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in mod_dav_lock in Apache HTTP Server 2.4.66 and earlier allows remote attackers to crash the server via a malicious request. The module dereferences a null pointer while processing the crafted DAV request, but Apache has not identified the request field or function involved. Reachability requires mod_dav_lock plus a backend provider that uses it; Apache identifies only mod_dav_svn from Subversion earlier than 1.2.0.

The record

CVE
CVE-2026-29169
Published
May 4, 2026
Updated
May 4, 2026
Vendor
The Apache Software Foundation
Product
Apache HTTP Server
Classifications
CWE-476, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 4, 2026CVE publishedPublication date reported by the CVE source.
  2. May 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2.4.66

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache HTTP Serverversion=0 <=2.4.66

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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