[pkg-vuln] CVE-2026-102271 in pyjwt@2.13.0 #895

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kert · 2026-09-30T06:01:58Z

kert commented

2026-09-30 06:01:58 +00:00

Severity: HIGH
Package: pyjwt @ 2.13.0
Fixed in: 2.14.0

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 supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens.

Reference: https://nvd.nist.gov/vuln/detail/CVE-2026-102271

**Severity:** HIGH **Package:** `pyjwt` @ `2.13.0` **Fixed in:** `2.14.0` 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 supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. **Reference:** https://nvd.nist.gov/vuln/detail/CVE-2026-102271

kert added this to the P21: Package Supply Chain — inventory, mirrors, drift, vuln scanning milestone 2026-09-30 06:01:58 +00:00

kert added the quality ci labels 2026-09-30 06:01:58 +00:00

kert closed this issue

2026-10-27 16:15:14 +00:00

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Reference: homelab/stack#895