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.
- Published Sep 8, 2026
- CVSS 8.6 high
- 0.9% chance of exploitation in the next 30 days (EPSS)
- Public exploit code is available
- A fix is available