Path Traversal in Xenforo
CVE-2026-74239
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.
Vulnerability class: Path Traversal (Directory Traversal)
CVSS v3 metric
CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- disclosure@vulncheck.com (vendor-advisory, patch)
- disclosure@vulncheck.com (release-notes)
- disclosure@vulncheck.com (third-party-advisory)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (exploit)
Frequently asked questions
- What is CVE-2026-74239?
- CVE-2026-74239 is a high-severity vulnerability in Xenforo, classified under Path Traversal. CVSS score: 7.2/10. Published 2026-09-08.
- How severe is CVE-2026-74239?
- High severity. CVSS v3 base score is 7.2 out of 10.
- Is CVE-2026-74239 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.