CVE-2026-61511: vBulletin · Eval Injection
Affects vBulletinSource CVE Database V5
Public exploit available · CVSS 9.3 Critical.
Data as of 3 Nov 2026, 22:58 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 9.3 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 9.8 |
- EPSS
- 5.6% chance of exploitation in 30 days – higher than 92% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-14.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 27 Jul 2026
Detectable: evidence found.
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by VulnCheck
, 17 days before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 79 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 3 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| vBulletinvBulletin | Affected
| Fixed in– |
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.
References
- karmainsecurity.com/KIS-2026-13 (opens in a new tab)
- ssd-disclosure.com/vbulletin-runtime-template-runmaths-preauth-rce/ (opens in a new tab)
- 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 (opens in a new tab)
- forum.vbulletin.com/forum/vbulletin-announcements/vbulletin-announcements_aa/4509404-vbulletin-6-2-2-is-available (opens in a new tab)
- vulncheck.com/advisories/vbulletin-eval-injection-rce-via-vb5-template-runtime-php (opens in a new tab)
- seclists.org/fulldisclosure/2026/Aug/29 (opens in a new tab)