CVE-2026-63408
CVE-2026-63408 is a high-severity vulnerability with a CVSS 3.x base score of 7.5. 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-598.
Key facts
- Severity: High (CVSS 3.x base score 7.5)
- EPSS exploit prediction: 0% (29th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-598
- 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 JwtAuthenticator::extractBearerToken() accepts a JWT from the token URL query parameter on every /api/v1 route, including state-changing endpoints. Request URLs consequently expose valid access tokens through Apache, proxy, and CDN logs, browser history, and Referer headers, allowing a party with access to those records to reuse the token with the owner's API privileges. This issue is fixed in version 1.0.0-rc.16.
Frequently asked questions
- What is CVE-2026-63408?
- 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 JwtAuthenticator::extractBearerToken() accepts a JWT from the token URL query parameter on every /api/v1 route, including state-changing endpoints. Request URLs consequently expose valid access tokens through Apache, proxy, and CDN logs, browser history, and Referer headers, allowing a party with access to those records to reuse the token with the owner's API privileges. This issue is fixed in version 1.0.0-rc.16.
- How severe is CVE-2026-63408?
- CVE-2026-63408 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
- Is CVE-2026-63408 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (29th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-63408?
- 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-2026-63408 published?
- CVE-2026-63408 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-4hpj-wmpw-ghwq
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