Unauthorized token issuance via conjunctive code validation
Published Mar 9, 2026 · Updated Mar 9, 2026
Incorrect authorization in Pocket ID before 2.4.0 allows remote authenticated users to obtain tokens through the OIDC token endpoint. In backend/internal/service/oidc_service.go, the endpoint rejects a code only when its client ID is wrong and it is expired, using conjunction where either failure must reject it. An OIDC client operator can exchange codes issued to other clients for user tokens, and a correct client can reuse an expired code until the 24-hour cleanup job removes it.
Summary
What happened
Incorrect authorization in Pocket ID before 2.4.0 allows remote authenticated users to obtain tokens through the OIDC token endpoint. In backend/internal/service/oidc_service.go, the endpoint rejects a code only when its client ID is wrong and it is expired, using conjunction where either failure must reject it. An OIDC client operator can exchange codes issued to other clients for user tokens, and a correct client can reuse an expired code until the 24-hour cleanup job removes it.
The record
- CVE
- CVE-2026-28513
- Published
- Mar 9, 2026
- Updated
- Mar 9, 2026
- Vendor
- Pocket ID
- Product
- Pocket ID
- Classifications
- CWE-863, T1528
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 9, 2026CVE publishedPublication date reported by the CVE source.
- Mar 9, 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=< 2.4.0
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.
Public exploit references
- GHSA cross-client authorization-code exchange proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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