CVE-2026-61511 Details
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.
An eval injection vulnerability has been identified in vBulletin versions 5.x prior to 5.7.5 and 6.x prior to 6.2.1. The issue resides in the vB5_Template_Runtime::runMaths() method within the template runtime. This vulnerability allows unauthenticated remote attackers to execute arbitrary PHP code by sending crafted input through the pagenav[pagenumber] parameter. Exploitation is possible via the ajax/render template route, taking advantage of an insufficiently restrictive regex filter by using phpfuck-style encoding with permitted characters to inject and execute PHP code.
Users are advised to upgrade to vBulletin version 6.2.2 or apply the security patch released for vBulletin versions 6.2.1, 6.2.0, and 6.1.6.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Jul 27, 2026CISA-ADP
Assessed Jul 28, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| http://seclists.org/fulldisclosure/2026/Aug/29 | CVE | |
| 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 | [email protected] | AdvisoryPermission RequiredRemedyVendor |
| https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4509404-vbulletin-6-2-2-is-available | [email protected] | Release NotesVendor |
| https://karmainsecurity.com/KIS-2026-13 | [email protected] | ExploitRemedyTechnical Description |
| https://ssd-disclosure.com/vbulletin-runtime-template-runmaths-preauth-rce/ | [email protected] | AdvisoryExploitRemedy |
| https://www.vulncheck.com/advisories/vbulletin-eval-injection-rce-via-vb5-template-runtime-php | [email protected] | AdvisoryBundle |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-95 | Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| vBulletin | <= 5.7.5 (semver) <= 6.2.1 (semver) |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 7, 2026 | CVE Modified | CVE |
| Jul 29, 2026 | CVE Modified | CISA-ADP |
| Jul 28, 2026 | CVE Modified | CISA-ADP |
| Jul 27, 2026 | CVE Modified | CISA-ADP |
| Jul 27, 2026 | New CVE Received | [email protected] |