CVE-2026-61511: exploitation status and patch state

CVE-2026-61511 · CVSS 9.8 CRITICAL

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.

Is CVE-2026-61511 exploited?

• Not in the CISA KEV catalog.
• Public exploit code: none found in monitored sources.

Which products and versions are affected?

No affected package list recorded here yet.

Is there a patch?

No patch identifier recorded here yet.

What PlainSec published about CVE-2026-61511

• Public Exploit Turns vBulletin Into a Server Foothold (2026-07-29)

Primary sources

• NVD record

What this record does not say

• No EPSS score.
• No affected package data.
• No patch identifier.

KEV and EPSS are re-checked daily. Record last updated 2026-08-11.