CVEs / CVE-2026-61511
CVE-2026-61511: vBulletin vBulletin vulnerability
- critical 9.3 CVSS 4.0 (from the CNA)
- EPSS 74.2% chance of exploitation in the next 30 days, higher than 99% of CVEs (14 Nov 2026)
- Last changed at its sources
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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 and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| vBulletin vBulletin | from 5.0.0, up to and including 5.7.5 | — |
| vBulletin vBulletin | from 6.0.0, up to and including 6.2.1 | — |
Exploitation
Not in the CISA Known Exploited Vulnerabilities catalog as of 13 Nov 2026.
Severity
| CVSS 4.0 | 9.3 criticalCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-95 |
References
- CVE-2026-61511 on NVD
- 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
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.