CVE-2026-63407
CVE-2026-63407 is a high-severity vulnerability with a CVSS 3.x base score of 8.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-942.
Key facts
- Severity: High (CVSS 3.x base score 8.2)
- EPSS exploit prediction: 0% (19th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-942
- Published:
- Last modified:
Description
Grav 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.
Frequently asked questions
- What is CVE-2026-63407?
- Grav 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.
- How severe is CVE-2026-63407?
- CVE-2026-63407 has a CVSS 3.x base score of 8.2, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity low, and availability none.
- Is CVE-2026-63407 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (19th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-63407?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2026-63407 published?
- CVE-2026-63407 was published on 2026-08-19.
References
- https://github.com/getgrav/grav-plugin-api/commit/56ae2ca3bf36c8299a4b3d376c6a20e8c0ed5ba9
- https://github.com/getgrav/grav-plugin-api/releases/tag/1.0.0-rc.16
- https://github.com/getgrav/grav/security/advisories/GHSA-93px-98wh-6fj2
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