CVE-2026-61511
CRITICAL
9.8
CVSS 3.1
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.
Metadata
Severity & Metrics
9.8
CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC — CISA Coordinator
Affected products (1)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| vBulletin | vBulletin | — | 5.0.0 ≤ 5.7.5, 6.0.0 ≤ 6.2.1, 6.2.2 |
Weakness (CWE)
| CWE | Source | Description |
|---|---|---|
| CWE-95 | cna | Improper Neutralization of Directives in Dynamically Evaluated Code ('Eval Injection') |
CVSS scores (2)
| Score | Severity | Version | Source | Vector |
|---|---|---|---|---|
| 9.8 | CRITICAL | 3.1 | cna | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 9.3 | CRITICAL | 4.0 | cna | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
References (5)
- Karma(In)Security Disclosure https://karmainsecurity.com/KIS-2026-13
- SSD Secure Disclosure https://ssd-disclosure.com/vbulletin-runtime-template-runmaths-preauth-rce/
- 6.2.1, 6.2.0, 6.1.6 Security Announcement 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
- 6.2.2 Release Notes https://forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4509404-vbulletin-6-2-2-is-available
- https://www.vulncheck.com/advisories/vbulletin-eval-injection-rce-via-vb5-template-runtime-php