CVE-2026-35056: XenForo Remote Code Execution via Authenticated Admin

Severity: high (CVSS 7.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-04-01 · updated 2026-06-17
Weakness: CWE-94

Description

XenForo before 2.3.9 and before 2.2.18 allows remote code execution (RCE) by authenticated, but malicious, admin users. An attacker with admin panel access can execute arbitrary code on the server.

Affected products

XenForo: before 2.2.18; from 2.3.0 before 2.3.9 — fixed in 2.2.18, 2.3.9

How to fix

Upgrade to a fixed version: XenForo 2.2.18, 2.3.9. Check the vendor advisory for mitigations.

References

https://www.vulncheck.com/advisories/xenforo-remote-code-execution-via-authenticated-admin
https://xenforo.com/community/threads/xenforo-2-3-9-inc-xfmg-2-2-18-released-security-fix.235659/

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