CVE-2026-72701

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 4.0

6.3CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 11% of CVEs (scores of 2026-10-25)

CWE

CWE-208

Published

2026-08-25

Modified

2026-10-12

Record from

the NVD, synced 2026-10-19

References

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

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