EUVD-2026-88541

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...

CVE-2026-102273 PyJWT accepts public JWK containers as HMAC secrets

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...

CVE-2026-102271 PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.preparekey 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...

CVE-2026-102271 PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.preparekey 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...

CVE-2026-102271 PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.preparekey 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...

CVE-2026-102271

The PyJWT Python library (versions 2.4.0 through 2.14.0 ) is vulnerable in the HMACAlgorithm.prepare_key function. The root cause is that the asymmetric-key guard relies on textual markers that are missing from DER encoding . When an application mixes HMAC and asymmetric algorithms and provides a...

CVE-2026-102271

PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.preparekey 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...

CVE-2026-102268 PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

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

CVE-2026-102268

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

CVE-2026-102268

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

CVE-2026-102268

The PyJWT library (versions prior to 2.14.0 ) contains a vulnerability in jwt/utils.py where the is_pem_format function fails to recognize certain PEM representations accepted by the cryptography loader. This occurs when applications mixing HMAC and asymmetric algorithms provide mutated public-ke...

CVE-2026-102268 PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

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

EUVD-2026-88535

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

CVE-2026-102268 PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

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

CVE-2026-102266

The PyJWT library (Python implementation of JSON Web Token standards) is vulnerable in versions 2.13.0 through 2.14.0 due to a flaw in the HMACAlgorithm.from_jwk method. The PyJWK verification path fails to apply prepare_key validation when a trusted JWK Set contains an oct entry with an empty k ...

CVE-2026-102266 PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation

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-2026-102266 PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation

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-2026-102266 PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation

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-2026-59563

Zscaler MCP Server versions 0.7.0 and 0.7.1 has an issue where HMAC confirmation tokens were not bound to the target resource identifier, allowing an MCP client or agent to replay a token generated for one resource to affect another resource of the same type. This issue is fixed in version 0.7.2...

CVE-2026-59563 HMAC Confirmation Token Unbinding in zscaler-mcp-server

Zscaler MCP Server versions 0.7.0 and 0.7.1 has an issue where HMAC confirmation tokens were not bound to the target resource identifier, allowing an MCP client or agent to replay a token generated for one resource to affect another resource of the same type. This issue is fixed in version 0.7.2...