CVE-2025-66200: Apache HTTP Server: mod_userdir+suexec bypass via AllowOverride FileInfo

[Eric Covener <covener () apache org>]

Severity: moderate 

Affected versions:

- Apache HTTP Server 2.4.7 through 2..4.65

Description:

mod_userdir+suexec bypass via AllowOverride FileInfo vulnerability in Apache HTTP Server. Users with access to use the 
RequestHeader directive in htaccess can cause some CGI scripts to run under an unexpected userid.

This issue affects Apache HTTP Server: from 2.4.7 through 2.4.65.

Users are recommended to upgrade to version 2.4.66, which fixes the issue.

Credit:

Mattias Åsander (Umeå University) (finder)

References:

https://httpd.apache.org/security/vulnerabilities_24.html
https://httpd.apache.org/
https://www.cve.org/CVERecord?id=CVE-2025-66200

Timeline:

2025-11-19: reported
2025-12-01: fixed in 2.4.x by r1930168