CVE-2026-74239
XenForo < 2.3.13 Path Traversal via Style Archive Importer on Windows
HIGH 8.6EPSS 0.9%
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.
- Affected
- XenForo
- CVSS v4.0 VULNCHECK
- 8.6 HIGH
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS v3.1 VULNCHECK
- 7.2 HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - EPSS
- 0.89% chance of exploitation in the next 30 days, 59th percentile
- Published
- 2026-09-08
- Updated
- 2026-10-01
Proof-of-concept exploits (1)
- BomboBombone/CVE-2026-742390★ · 2026-09-08
Security advisories
- https://bombobombone.github.io/posts/cve-2026-74239
- https://www.vulncheck.com/advisories/xenforo-path-traversal-via-style-archive-importer-on…
- https://xenforo.com/community/threads/security-fixes-released-for-all-xenforo-and-media-g…
- https://xenforo.com/community/threads/xenforo-2-3-13-and-add-ons-released-includes-securi…