CVE-2026-72701

Description

Grav CMS before 2.0.16 contains a timing vulnerability in Utils::verifyNonce() that uses non-constant-time string comparison with the === operator instead of hash_equals() for CSRF nonce validation. Attackers can measure response timing differences to recover valid nonce values byte-by-byte through multiple requests, weakening CSRF protection below its intended security margin.

CVSS Vector

References

• https://github.com/getgrav/grav/security/advisories/GHSA-38p6-h87p-r4cg
• https://www.vulncheck.com/advisories/grav-cms-before-timing-attack-via-verifynonce