CVE-2026-61511
Code injection
- Published27 Jul 2026
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.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
- http://seclists.org/fulldisclosure/2026/Aug/29
- 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
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-61511 being actively exploited?
CVE-2026-61511 is not in the CISA KEV catalog. Its EPSS exploit probability is 5.61%.
How severe is CVE-2026-61511?
CVE-2026-61511 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 5.61% probability of exploitation.
How do I fix CVE-2026-61511?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-61511 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.