Apache HTTP Server up to 2.4.67 mod_xml2enc heap-based overflow

Summaryinfo

A vulnerability identified as critical has been detected in Apache HTTP Server up to 2.4.67. Affected is an unknown function of the component mod_xml2enc. The manipulation leads to heap-based overflow. This vulnerability is listed as CVE-2026-42536. The attack may be initiated remotely. There is no available exploit. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Apache HTTP Server up to 2.4.67 and classified as critical. This issue affects some unknown functionality of the component mod_xml2enc. The manipulation with an unknown input leads to a heap-based overflow vulnerability. Using CWE to declare the problem leads to CWE-122. A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). Impacted is confidentiality, integrity, and availability. The summary by CVE is:

Heap-based Buffer Overflow vulnerability in Apache HTTP Server with mod_xml2enc, xml2StartParse, and untrusted content 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.

It is possible to read the advisory at lists.apache.org. The identification of this vulnerability is CVE-2026-42536. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/13/2026).

The vulnerability scanner Nessus provides a plugin with the ID 319665 (Apache 2.4.x < 2.4.68 Multiple Vulnerabilities), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.4.68 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (319665) and EUVD (EUVD-2026-35100). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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
• 2.4.67

License

• open-source

Website

• Vendor: https://www.apache.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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