CVE-2026-72701

Grav CMS before 2.0.16 Timing Attack via verifyNonce

Published Aug 25, 2026 CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-38p6-h87p-r4cg Grav: Non constant time nonce comparison in Utils::verifyNonce() used for CSRF protection
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Grav CMS before 2.0.16 Timing Attack via verifyNonce
First Time appeared Getgrav
Getgrav grav
Weaknesses CWE-208
CPEs cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*
Vendors & Products Getgrav
Getgrav grav
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N'}

cvssV4_0

{'score': 6.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Oct 8, 2026, 3:24 PM
Reserved
Aug 10, 2026, 1:02 PM
Status
Deferred
Published
Aug 25, 2026, 2:16 AM
Modified
Oct 12, 2026, 3:10 PM