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)
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.009 (58.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- Vendor Advisory (vendor-advisory, patch, Release Notes)
- Release Notes (release-notes, Release Notes)
- www.vulncheck.com/advisories/xenforo-path-traversal-via-style-archive-importer-… (Third Party Advisory, third-party-advisory)
- Researcher Advisory (Exploit, technical-description, Third Party Advisory)
- Researcher PoC (Exploit, exploit, Third Party Advisory)
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.