JWT disclosure via reflected CORS origin
Published Aug 19, 2025 · Updated Aug 19, 2025
CORS misconfiguration in Nginx Proxy Manager 2.12.3 allows remote attackers to read JWT tokens through attacker-controlled origins. The /api/tokens endpoint reflects an untrusted Origin value in Access-Control-Allow-Origin, letting browser code read the token-bearing response and forward its JWT off-site. Exploitation requires a browser request that submits valid application credentials, and the resulting token permits impersonation and access within those credentials' privileges.
Summary
What happened
CORS misconfiguration in Nginx Proxy Manager 2.12.3 allows remote attackers to read JWT tokens through attacker-controlled origins. The /api/tokens endpoint reflects an untrusted Origin value in Access-Control-Allow-Origin, letting browser code read the token-bearing response and forward its JWT off-site. Exploitation requires a browser request that submits valid application credentials, and the resulting token permits impersonation and access within those credentials' privileges.
The record
- CVE
- CVE-2025-50579
- Published
- Aug 19, 2025
- Updated
- Aug 19, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-1259, T1550.001
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 19, 2025CVE publishedPublication date reported by the CVE source.
- Aug 19, 2025Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- Issue 4509 browser-script proof of conceptproof of concept · demonstrated
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Technologies
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