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CVE-2026-63408

HIGH 7.5

Published 2026-08-19 · Last modified 2026-08-19

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.

ELEVATED IMPACT

Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.4%chance of exploitation in 30 days · 29th percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

  • ConfidentialityHigh
  • IntegrityNone
  • AvailabilityNone

What an attacker needs

  • Access: Reachable over the network — no local access needed
  • Privileges: No account or privileges required
  • User interaction: No user interaction needed
  • Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-63408/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-2026-63408/poc.json

Affected

Vendors Getgrav

Products Grav Plugin Api

Weakness (CWE)

  • CWE-598: : Use of GET Request Method With Sensitive Query Strings

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

All CVSS metrics

  • HIGH 7.5 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
  • HIGH 7.5 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Sources: NVD · CVE.org · EPSS