CVE-2026-74239

What it is

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.

At a glance

Exploitability

Can be exploited over the network with an admin-level account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.9% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-09-08 14:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-11 20:30 UTC Last updatedMost recent change to the record

Details

Published

2026-09-08 14:17 UTC

Last modified

2026-09-11 20:30 UTC

Exploit probability

0.9% · EPSS, next 30 days

Weakness

CWE-22 · Path traversal

Record status

Analyzed

Affected

• Xenforo < 2.3.13

Attack profile CVSS 4.0 · 8.6

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

High

User interaction

None

Confidentiality

High

Integrity

High

Availability

High