CVE-2026-102266: Improper Verification of Cryptographic Signature

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.fromjwk is affected because PyJWK verification path used the decoded key without applying preparekey validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. As...

CVE-2026-102272: Improper Verification of Cryptographic Signature

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.preparekey in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with ...

PT-2026-108338

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and...

PT-2026-108344

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.from jwk is affected because PyJWK verification path used the decoded key without applying prepare key validation. This occurs when a trusted JWK Set contains an oct entry with an empty k value. ...

PT-2026-102365

Name of the Vulnerable Software and Affected Versions PyJWT versions 2.13.0 through 2.13.x Description The HMACAlgorithm.prepare key function is affected because the HMAC key guard only recognizes top-level public JSON Web Key JWK forms and fails to identify container representations. This occurs...

CVE-2026-102273: Improper Verification of Cryptographic Signature

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWT HMACAlgorithm.preparekey 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...

PT-2026-108328

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, is pem format in jwt/utils.py is affected because is pem format does not recognize every PEM representation accepted by the cryptography loader. This occurs when an application mixes HMAC and asymmetric algorithms and...

PT-2026-108339

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.prepare key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with...

PT-2026-108327

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT is pem format is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, is pem...

CVE-2026-102270: Inefficient Regular Expression Complexity

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT ispemformat is affected because lazy PEM regular expression backtracks extensively. This occurs when a certificate-like input contains repeated BEGIN markers without a matching END marker. As a result, ispemforma...

PT-2026-102362

Name of the Vulnerable Software and Affected Versions PyJWT versions prior to 2.14.0 Description The is pem format function is affected by a regular expression issue where lazy PEM processing causes extensive backtracking. This happens when input resembling a certificate contains repeated BEGIN...

PT-2026-108325

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT get signing key from jwt is affected because unknown kid misses force refreshes without a negative cache or minimum refresh interval. This occurs when unauthenticated tokens repeatedly use the same unknown kid or...

PT-2026-108337

PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.get signing key from jwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. ...

PT-2026-108342

PyJWT is a Python implementation of JSON Web Token standards. From 2.1.0 until 2.15.0, PyJWT OKPAlgorithm.from jwk in jwt/algorithms.py is affected because private-JWK import path does not compare the public key derived from d with x. This occurs when an OKP private JWK supplies non-corresponding...

PT-2026-102348

Name of the Vulnerable Software and Affected Versions PyJWT versions 2.0.0a1 through 2.14.9 Description The PyJWKClient.get signing key from jwt function and the jwt/api jwt.py implementation when verify signature=False are affected by an issue where the payload parser catches ValueError but fail...

CVE-2026-101918: Uncaught Exception

PyJWT is a Python implementation of JSON Web Token standards. From 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.getsigningkeyfromjwt is affected because payload parser catches ValueError but not RecursionError. This occurs when an attacker-controlled recursively nested payload reaches json.loads. As a...

CVE-2026-102269: Incorrect Behavior Order: Validate Before Canonicalize

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT signature segment is affected because signature segment decoding accepts characters outside the canonical Base64URL representation. This occurs when non-Base64URL characters are appended to a valid compact JWS...

PT-2026-102361

Name of the Vulnerable Software and Affected Versions PyJWT versions prior to 2.14.0 Description PyJWT is a Python implementation of JSON Web Token standards. The signature segment decoding process accepts characters outside the canonical Base64URL representation when non-Base64URL characters are...

PT-2026-108326

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT signature segment is affected because signature segment decoding accepts characters outside the canonical Base64URL representation. This occurs when non-Base64URL characters are appended to a valid compact JWS...

PT-2026-108341

PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, PyJWS. load in jwt/api jws.py is affected because parser catches ValueError but not RecursionError. This occurs when a deeply nested token header reaches json.loads. As a result, RecursionError escapes the...