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TI-2026-50939 Aliases CVE-2026-72701GHSA-38p6-h87p-r4cg

Grav CMS before 2.0.16 Timing Attack via verifyNonce

Priority MEDIUM 61CWE-208Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
Information disclosure
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-208.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00216 12th percentileScored 2026-11-07
Fix Fixed grav (getgrav): 2.0.16getgrav/grav (Packagist): 2.0.16

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
getgravgravbefore 2.0.162.0.16Patch availableCNA
—getgrav/grav (Packagist)before 2.0.162.0.16Patch availableGHSA-38p6-h87p-r4cg
  • grav Vendorgetgrav Affected before 2.0.16 Fixed in 2.0.16 Patch available CNA
  • getgrav/grav (Packagist) Vendor— Affected before 2.0.16 Fixed in 2.0.16 Patch available GHSA-38p6-h87p-r4cg

Remediation

  • Fix · CNA grav (getgrav) Fixed in 2.0.16
  • Fix · GHSA-38p6-h87p-r4cg getgrav/grav (Packagist) Fixed in 2.0.16 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    getgrav grav 2.0.16

    8 records Highest priority Priority HIGH 4 HIGH, 3 MEDIUM, 1 LOW

    Other records, highest priority first

    • TI-2026-50940 Grav CMS before 2.0.16 Origin Validation Bypass via RefererPriority HIGH 81
    • TI-2026-53682 Grav before 2.0.16 Information Disclosure via Twig SandboxPriority HIGH 77
    • TI-2026-50934 Grav CMS before 2.0.16 Symlink Following via createLockFilePriority HIGH 72
    Show all 8 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-72701
  2. 2026-10-03 Alias added: GHSA-38p6-h87p-r4cg

References

Advisory 2

Other 3

  • TI-2026-30893 Grav: Privilege Escalation via Missing Server-Side Validation of groups/access CVSS 3.1CRITICAL 9.4
  • TI-2025-28971 Cross Site Scripting vulnerability in grav v.1.7.48 and before allows an attacker to… CVSS 3.1CRITICAL 9.8
  • TI-2021-04523 Unauthenticated Arbitrary YAML Write/Update leads to Code Execution CVSS 3.1CRITICAL 9.8
  • TI-2026-50940 Grav CMS before 2.0.16 Origin Validation Bypass via Referer CVSS 4.0CRITICAL 9.3
  • TI-2026-46446 Grav before 2.0.7 Remote Code Execution via Blueprint dynamicData CVSS 4.0CRITICAL 9.3
  • TI-2021-22428 GravCMS 1.10.7 - Arbitrary YAML Write/Update (Unauthenticated) (2) CVSS 4.0CRITICAL 9.3
See all 228 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences