PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because HMAC key guard only recognizes top-level public JWK forms and misses container representations. This occurs when an application allows HMAC and asymmetric algorithms and passes a public JWK container as the raw key. As a result, public asymmetric key material is accepted as the HMAC secret. Consequently, an attacker who knows the public key can forge a token with arbitrary authenticated claims. This issue is fixed in version 2.14.0.
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History
Tue, 06 Oct 2026 18:45:00 +0000
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Pyjwt Project
Pyjwt Project pyjwt |
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| CPEs | cpe:2.3:a:pyjwt_project:pyjwt:2.13.0:*:*:*:*:*:*:* | |
| Vendors & Products |
Pyjwt Project
Pyjwt Project pyjwt |
Tue, 29 Sep 2026 17:30:00 +0000
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ssvc
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Tue, 29 Sep 2026 13:15:00 +0000
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threat_severity
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threat_severity
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Mon, 28 Sep 2026 23:15:00 +0000
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Jpadilla
Jpadilla pyjwt |
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| Vendors & Products |
Jpadilla
Jpadilla pyjwt |
Mon, 28 Sep 2026 21:00:00 +0000
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| Description | PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because HMAC key guard only recognizes top-level public JWK forms and misses container representations. This occurs when an application allows HMAC and asymmetric algorithms and passes a public JWK container as the raw key. As a result, public asymmetric key material is accepted as the HMAC secret. Consequently, an attacker who knows the public key can forge a token with arbitrary authenticated claims. This issue is fixed in version 2.14.0. | |
| Title | PyJWT accepts public JWK containers as HMAC secrets | |
| Weaknesses | CWE-347 | |
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cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-09-28T20:38:28.161Z
Updated: 2026-09-29T13:44:49.200Z
Reserved: 2026-09-28T20:11:16.658Z
Link: CVE-2026-102273
Updated: 2026-09-29T13:44:31.737Z
Status : Analyzed
Published: 2026-09-28T21:17:15.497
Modified: 2026-10-06T18:29:42.883
Link: CVE-2026-102273