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TI-2026-42221 Aliases CVE-2026-58656GHSA-fx5h-wv8r-5j9q

Grav API Plugin - Cross-Origin Admin Account Takeover via CORS Wildcard and JWT Query Parameter

Priority HIGH 77CWE-598Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
High · None · None
Fix status
No fix listed

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

Summary

Grav API plugin before v1.0.0-rc.16 accepts JWT tokens via the ?token= URL query parameter and responds with Access-Control-Allow-Origin: *, allowing unauthenticated attackers to make fully authenticated cross-origin API requests from any malicious website. Attackers who obtain a leaked JWT token from access logs, proxy logs, browser history, or Referrer headers can create persistent backdoor super-admin accounts and exfiltrate sensitive configuration and user data.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00354 29th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
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
getgravgravup to 1.0.0-rc.15—No fix listedCNA
  • grav Vendorgetgrav Affected up to 1.0.0-rc.15 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-58656
  2. 2026-10-03 Alias added: GHSA-fx5h-wv8r-5j9q

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