CVE-2023-25135: vBulletin

Critical severity, CVSS 9.8. EPSS: 23.9% chance of exploitation in the next 30 days.

vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization. This occurs because verify_serialized checks that a value is serialized by calling unserialize and then checking for errors. The fixed versions are 5.6.7 PL1, 5.6.8 PL1, and 5.6.9 PL1.

Affected products

• vBulletin vBulletin: version 5.6.7 only; version 5.6.8 only; version 5.6.9 only

Published 2023-02-03. Last modified 2026-06-17.