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CRITICAL

CVE-2026-61511

CVSS v3

9.8

CRITICAL

EPSS Score

1.3 %

exploit probability

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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

Technical details

CVSS v3 Vector
3.1
Published
2026-07-27
Last Modified
2026-07-28

Frequently asked questions

What is 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 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

Is CVE-2026-61511 actively exploited?

Active exploitation of CVE-2026-61511 has not been confirmed. The EPSS score is 1.3%, indicating the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-61511?

CVE-2026-61511 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string 3.1.

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