Read the docs
TI-2026-44058 Aliases CVE-2026-61453GHSA-2c4f-86xc-cr74

Grav before 2.0.1 XSS via Twig String Concatenation

Priority MEDIUM 56CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Active
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting, Code execution
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79 and CWE-1336.

Summary

Grav v2.0.0 contains a cross-site scripting vulnerability (fixed in 2.0.1). The XSS blueprint validator (Security::detectXss()) runs on raw page content before Twig processing. When Twig content processing is enabled (twig_content.process_enabled: true), an attacker with page-write API permission can use Twig's string concatenation operator (~) to dynamically construct event handler names, dangerous tag names, or dangerous protocols at render time (e.g. {% set x = "on" ~ "error" %}). The validator sees only the harmless Twig expression and allows the content, but after Twig rendering the output (rendered via {{ page.content|raw }}) contains an active payload such as <img src=1 onerror=alert(1)>, executing arbitrary JavaScript in visitors' browsers.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00196 9th percentileScored 2026-11-07
Fix Fixed grav (getgrav): 2.0.1getgrav/grav (Packagist): 2.0.1

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 2.0.12.0.1Patch availableCNA
—getgrav/grav (Packagist)2.0.0 to before 2.0.12.0.1Patch availableGHSA-2c4f-86xc-cr74
  • grav Vendorgetgrav Affected before 2.0.1 Fixed in 2.0.1 Patch available CNA
  • getgrav/grav (Packagist) Vendor— Affected 2.0.0 to before 2.0.1 Fixed in 2.0.1 Patch available GHSA-2c4f-86xc-cr74

Remediation

  • Fix · CNA grav (getgrav) Fixed in 2.0.1
  • Fix · GHSA-2c4f-86xc-cr74 getgrav/grav (Packagist) Fixed in 2.0.1 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-61453
  2. 2026-10-03 Alias added: GHSA-2c4f-86xc-cr74

References

Advisory 3

Other 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