Critical Out-of-Bounds Write Vulnerability in Apache HTTP Server (CVE-2026-59685)

apache2 Updated 03 Oct 2026

Summary

01/10/2026

Disclosed on

N/A

Severity

Yes i

Fix available

High

Severity

7.5

CVSS Score

ALPINE-CVE-2026-59685: Out-of-bounds Write vulnerability in Apache HTTP Server on Windows while processing paths with 8.3 names that may grow when expanded. Affects apache2 versions < 2.4.69-r0. Fixed in 2.4.69-r0. How to fix ↓

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Background

Apache HTTP Server is a widely-used open-source web server software that enables users to serve web content over the internet. Known for its flexibility, security features, and extensive documentation, Apache HTTP Server supports various modules and configurations, making it a popular choice for hosting websites. However, certain versions of this software are vulnerable to an out-of-bounds write issue, particularly when processing paths with 8.3 names on Windows systems.

Vulnerability Detail

The vulnerability identified as CVE-2026-59685 is an out-of-bounds write flaw in the Apache HTTP Server, specifically affecting versions from 2.4.0 to 2.4.68. This issue arises when the server processes file paths that utilize the 8.3 naming convention, which can expand in size during processing. If exploited, this vulnerability could allow an attacker to write data outside the intended memory bounds, potentially leading to arbitrary code execution or system crashes. The severity of this vulnerability is underscored by its CVSS score of 7.5, indicating a high risk to affected systems.

How To Fix

Minimum fixed version

2.4.69-r0

This is the first release that contains the fix.

sudo apk add --upgrade apache2

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Workaround

As a temporary workaround, users can disable the processing of 8.3 file names in their Windows environment. This can be done by modifying the system settings to prevent the use of legacy file naming conventions, although this may affect compatibility with certain applications.

Conclusion

CVE-2026-59685 represents a significant security risk for users of Apache HTTP Server versions 2.4.0 to 2.4.68. By understanding the nature of this vulnerability and taking the necessary steps to update to a patched version, users can protect their systems from potential exploitation.

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