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.
Published: 2026-08-25
Score: 6.3 Medium
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Tue, 25 Aug 2026 02:00:00 +0000

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'}

Subscriptions

Getgrav Grav
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-08-25T01:30:23.965Z

Reserved: 2026-08-10T13:02:20.829Z

Link: CVE-2026-72701

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-25T02:16:45.980

Modified: 2026-08-25T02:16:45.980

Link: CVE-2026-72701

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-208

    Observable Timing Discrepancy