CVE-2026-61511: 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 un
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.
Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-61511
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Moderate exploitation riskCVE-2026-615111.3% 30-day exploitation probability. Patch within normal cadence, watch for KEV listing. Riskier than 67% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-61511 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- critical[NEW] [critical] vBulletin: Vulnerability allows code executioncert-bund
Recent advisories for vBulletin
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
- critical[NEW] [critical] vBulletin: Vulnerability allows code executioncert-bund · 2026-07-28
- criticalexploitedCVE-2020-17496: vBulletin PHP Module Remote Code Execution Vulnerabilitycisa-kev · 2021-11-03
- criticalexploitedCVE-2019-16759: vBulletin PHP Module Remote Code Execution Vulnerabilitycisa-kev · 2021-11-03
More from NVD Recent CVEs
- unknownCVE-2026-18556: Authentication bypass using an alternate path or channel vulnerability in N-able N-central all…2026-08-01
- unknownCVE-2026-55735: Improper Verification of Cryptographic Signature in ueberauth guardian allows an unauthenticat…2026-08-01
- unknownCVE-2026-55734: Allocation of Resources Without Limits or Throttling vulnerability in ueberauth guardian (Guar…2026-08-01
- unknownCVE-2026-55733: Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of se…2026-08-01
- unknownCVE-2026-54894: Allocation of Resources Without Limits or Throttling in ueberauth guardian allows denial of se…2026-08-01