CVE-2026-74239
Severity CVSS v4.0:
HIGH
Type:
CWE-22
Path Traversal
Publication date:
08/09/2026
Last modified:
09/09/2026
Description
XenForo before 2.3.13 contains a path traversal vulnerability in the style archive importer on Windows deployments that allows authenticated non-super administrators with style permissions to write arbitrary files outside the intended extraction directory by using backslash-based traversal sequences in ZIP member names. Attackers can craft a malicious ZIP archive with backslash path separators that bypass forward-slash validation to write arbitrary bytes to any web-server-writable path, including the public web root, achieving persistent code execution as the web-server account.
Impact
Base Score 4.0
8.60
Severity 4.0
HIGH
Base Score 3.x
7.20
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://bombobombone.github.io/posts/cve-2026-74239/
- https://github.com/BomboBombone/CVE-2026-74239
- https://www.vulncheck.com/advisories/xenforo-path-traversal-via-style-archive-importer-on-windows
- https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-gallery-versions-2-2-0-2-3-12.239856/
- https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-security-fixes.239857/