Cross-origin account takeover via wildcard CORS
Published Aug 19, 2026 · Updated Aug 25, 2026
CORS misconfiguration in GetGrav Grav API Plugin before 1.0.0-rc.16 allows remote attackers to access API data with a stolen token. CorsMiddleware returns a wildcard origin and permissive preflight responses for authenticated API routes, so browsers expose reads and writes to JavaScript from any origin. Exploitation requires an attacker-obtained JWT or API token and a user visit to attacker-controlled content; resulting actions inherit the token owner's privileges.
Summary
What happened
CORS misconfiguration in GetGrav Grav API Plugin before 1.0.0-rc.16 allows remote attackers to access API data with a stolen token. CorsMiddleware returns a wildcard origin and permissive preflight responses for authenticated API routes, so browsers expose reads and writes to JavaScript from any origin. Exploitation requires an attacker-obtained JWT or API token and a user visit to attacker-controlled content; resulting actions inherit the token owner's privileges.
The record
- CVE
- CVE-2026-63407
- Published
- Aug 19, 2026
- Updated
- Aug 25, 2026
- Vendor
- GetGrav
- Product
- Grav API Plugin
- Classifications
- CWE-942, T1550.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2026CVE publishedPublication date reported by the CVE source.
- Aug 25, 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=< 1.0.0-rc.16
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- GitHub advisory cross-origin fetch proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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