CVE-2026-42536

Analyzed Analyzed - Analysis Complete

Heap-based Buffer Overflow in Apache HTTP Server

Publication date: 2026-06-08

Last updated on: 2026-06-09

Assigner: Apache Software Foundation

Description

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.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-06-08

Last Modified

2026-06-09

Generated

2026-06-29

AI Q&A

2026-06-08

EPSS Evaluated

2026-06-27

NVD

CVE-2026-42536

EUVD

EUVD-2026-35100

Affected Vendors & Products

Vendor	Product	Version / Range
apache	http_server	From 2.4.0 (inc) to 2.4.68 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
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().

Attack-Flow Graph

Executive Summary

This vulnerability is a heap-based buffer overflow in the Apache HTTP Server, specifically involving the mod_xml2enc module and the xml2StartParse function when processing untrusted content.

A heap-based buffer overflow occurs when a program writes more data to a buffer located in the heap than it can hold, potentially leading to memory corruption.

Impact Analysis

Exploitation of this heap-based buffer overflow could allow an attacker to cause a crash or potentially execute arbitrary code on the affected server.

This could lead to denial of service or unauthorized control over the server running the vulnerable Apache HTTP Server versions from 2.4.0 through 2.4.67.

Mitigation Strategies

Users are recommended to upgrade Apache HTTP Server to version 2.4.68, which fixes the heap-based buffer overflow vulnerability in mod_xml2enc.

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