What’s Vulnerable › Vulnerabilities

CVE-2026-61511: vBulletin < 6.2.2 Eval Injection RCE via vb5/template/runtime.php

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 5.6% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-07-27 · updated 2026-10-14
• Weakness: CWE-95

Description

vBulletin 5.x through 5.7.5 and 6.x through 6.2.1 contains an eval injection vulnerability in the vB5_Template_Runtime::runMaths() method within the template runtime that allows unauthenticated remote attackers to execute arbitrary PHP code by supplying crafted input through the pagenav[pagenumber] parameter. Attackers can exploit the insufficiently restrictive regex filter by using phpfuck-style encoding with permitted characters to inject and execute arbitrary PHP code via the unauthenticated ajax/render template route without any authentication.

Affected products

• vBulletin: from 5.0.0 through 5.7.5; from 6.0.0 through 6.2.1

References

• https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4509358-security-patch-released-for-vbulletin-6-2-1-6-2-0-and-6-1-6
• https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4509404-vbulletin-6-2-2-is-available
• https://karmainsecurity.com/KIS-2026-13
• https://ssd-disclosure.com/vbulletin-runtime-template-runmaths-preauth-rce/
• https://www.vulncheck.com/advisories/vbulletin-eval-injection-rce-via-vb5-template-runtime-php
• http://seclists.org/fulldisclosure/2026/Aug/29

Get alerted when CVE-2026-61511 or the next vulnerability affects your stack