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.

Scoring

Severity
HIGH
CVSS base score
8.6
CVSS vector
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
CWE
CWE-22
Published
2026-09-08
Last modified
2026-09-09

Affected products

Weakness type

Related vulnerabilities

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