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TI-2026-30888 Aliases CVE-2026-42608GHSA-hmcx-ch82-3fv2

Grav: Unauthenticated Path Traversal & Arbitrary File Write in FormFlash component.

Priority HIGH 79CWE-22Published · Updated

Key facts

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

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

Summary

Grav is a file-based Web platform. Prior to 2.0.0-beta.2, there is a Path Traversal vulnerability within the FormFlash core component. By manipulating the session_id (passed as __form-flash-id in POST requests), an unauthenticated attacker can traverse the filesystem to create arbitrary directories and write an index.yaml file containing attacker-controlled data. This vulnerability can lead to unauthorized modification of application behavior, potential data integrity issues, and service disruption in production environments. This vulnerability is fixed in 2.0.0-beta.2.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00603 49th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed grav (getgrav): 2.0.0-beta.2getgrav/grav (Packagist): 2.0.0-beta.2

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Total

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 2.0.0-beta.22.0.0-beta.2Patch availableCNA
—getgrav/grav (Packagist)before 2.0.0-beta.22.0.0-beta.2Patch availableGHSA-hmcx-ch82-3fv2
  • grav Vendorgetgrav Affected before 2.0.0-beta.2 Fixed in 2.0.0-beta.2 Patch available CNA
  • getgrav/grav (Packagist) Vendor— Affected before 2.0.0-beta.2 Fixed in 2.0.0-beta.2 Patch available GHSA-hmcx-ch82-3fv2

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:*before 2.0.0Vulnerablegetgrav
cpe:2.3:a:getgrav:grav:2.0.0:beta1:*:*:*:*:*:*2.0.0 beta1Vulnerablegetgrav
  • cpe:2.3:a:getgrav:grav:*:*:*:*:*:*:*:* Versions before 2.0.0 Vulnerable ·getgrav
  • cpe:2.3:a:getgrav:grav:2.0.0:beta1:*:*:*:*:*:* Versions 2.0.0 beta1 Vulnerable ·getgrav

Remediation

  • Fix · CNA grav (getgrav) Fixed in 2.0.0-beta.2
  • Fix · GHSA-hmcx-ch82-3fv2 getgrav/grav (Packagist) Fixed in 2.0.0-beta.2 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-42608
  2. 2026-10-03 Alias added: GHSA-hmcx-ch82-3fv2

References

Exploit 1

Advisory 1

Other 3

  • 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-2021-22428 GravCMS 1.10.7 - Arbitrary YAML Write/Update (Unauthenticated) (2) CVSS 4.0CRITICAL 9.3
  • TI-2025-41064 In grav <1.7.49.5, a SSRF (Server-Side Request Forgery) vector may be triggered via Twig… CVSS 3.1CRITICAL 9.1
  • TI-2025-40773 Security Sandbox Bypass with SSTI (Server Side Template Injection) in the Grav CMS CVSS 3.1HIGH 8.8
  • TI-2025-40768 Grav is vulnerable to RCE via SSTI through Twig Sandbox Bypass CVSS 4.0HIGH 8.7
  • TI-2023-17087 Grav Server-side Template Injection via Insufficient Validation in filterFilter CVSS 3.1HIGH 8.8
See all 56 →

Sources

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