CVE-2026-63407
HIGH 8.2Grav API Plugin is a RESTful API for Grav CMS that provides full headless access to your site's content. Prior to 1.0.0-rc.16, the Grav API plugin CorsMiddleware returns Access-Control-Allow-Origin: * and permissive OPTIONS responses for authenticated /api/v1 endpoints. JavaScript from any origin can submit an attacker-obtained JWT through the Authorization or X-API-Token header, read the authenticated response, and perform write operations with the token owner's privileges, enabling data exfiltration and account modification. This issue is fixed in version 1.0.0-rc.16.
Severe if exploited (CVSS 8.2), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 19th percentile
Impact if exploited
8.2CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityLow
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ⚠User interaction: A user must take an action (click / open a file)
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-63407/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-63407/poc.json
Weakness (CWE)
- CWE-942: : Permissive Cross-domain Policy with Untrusted Domains
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N
All CVSS metrics
- HIGH 8.2 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N - HIGH 8.2 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N