PyJWT: HS256/384/512 verify accepts empty HMAC key via oct JWK (PyJWK/PyJWKClient) enabling token forgery
影響: pip:pyjwt <= 2.13.0 → 2.14.0
HMACAlgorithm.from_jwk accepts a symmetric (kty=oct) JWK whose k value is the empty string and returns a zero-length key without raising. When a token is then verified with that key object (a PyJWK, or a PyJWK resolved by PyJWKSet / PyJWKClient), the HMAC verifier computes HMAC(key=b"", signing_input) and accepts any token an attacker forged with the same empty key. The attacker needs no secret knowledge: they reproduce the digest locally with an empty key and set the token's kid to the empty-k…
| 정보원 | GitHub Advisory Database |
|---|---|
| 수집 시각 | 2026. 10. 23. 오전 05:09 |
| 데이터 | Markdown JSON |
2026. 10. 23. 오전 12:48, GitHub Advisory Database에서 "PyJWT: HS256/384/512 verify accepts empty HMAC key via oct JWK (PyJWK/PyJWKClient) enabling token forgery"을(를) 게시했습니다 (유형: 취약점 권고). 심각도는 "높음"(high)입니다. 관련 기술: Python.