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TI-2026-44277 Aliases CVE-2026-61873GHSA-m8gp-46r6-rc3f

Grav before 9.1.8 Arbitrary File Write via Twig-Processed Filename

Priority HIGH 65CWE-73Published · Updated

Key facts

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

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

Grav before 9.1.8 contains an arbitrary file write vulnerability in the Form plugin's process.save.filename parameter, which is validated against path traversal before Twig processing but never re-validated after rendering. Attackers can submit form data containing path traversal sequences that are processed through Twig templates, allowing them to write arbitrary files including PHP webshells to the web root or other sensitive directories.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00309 23rd percentileScored 2026-11-07
Fix Fixed grav (getgrav): 9.1.8

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 9.1.89.1.8Patch availableCNA
  • grav Vendorgetgrav Affected before 9.1.8 Fixed in 9.1.8 Patch available CNA

Remediation

  • Fix · CNA grav (getgrav) Fixed in 9.1.8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-61873
  2. 2026-10-03 Alias added: GHSA-m8gp-46r6-rc3f

References

Advisory 1

  • 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