Admin takeover via query-string JWT and wildcard CORS
Published Jul 8, 2026 · Updated Jul 8, 2026
Authentication bypass in the Grav API plugin before 1.0.0-rc.16 allows remote attackers with a leaked JWT to take over a site. The JwtAuthenticator::extractBearerToken fallback accepts token on every API route while CORS returns Access-Control-Allow-Origin: *. Possession of a token exposed through logs, Referrer headers, or browser history is required; it enables cross-origin data theft and persistent super-admin creation.
Summary
What happened
Authentication bypass in the Grav API plugin before 1.0.0-rc.16 allows remote attackers with a leaked JWT to take over a site. The JwtAuthenticator::extractBearerToken fallback accepts token on every API route while CORS returns Access-Control-Allow-Origin: *. Possession of a token exposed through logs, Referrer headers, or browser history is required; it enables cross-origin data theft and persistent super-admin creation.
The record
- CVE
- CVE-2026-58656
- Published
- Jul 8, 2026
- Updated
- Jul 8, 2026
- Vendor
- Grav
- Product
- Grav
- Classifications
- CWE-942, CWE-598, T1136
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 8, 2026CVE publishedPublication date reported by the CVE source.
- Jul 8, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=1.0.0-rc.15
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- GHSA query-string JWT and wildcard CORS proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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