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

Prerequisites both conditions must hold; both are deployment properties, not attacker-controlled at request time: - The jwt.decode allow-list mixes an HMAC algorithm with an asymmetric one, e.g. algorithms="ES256", "HS256" the RFC 8725 footgun the guard exists to backstop. - The verification key ...

PyJWT accepts public JWK containers as HMAC secrets

Summary PyJWT 2.13.0 contains an incomplete defense against algorithm confusion when an application mixes symmetric and asymmetric algorithms in one verification path. A public RSA, EC, or OKP JWK can be accepted as an HMAC secret when it is wrapped in a JWKS object, nested in an array, or...

GHSA-W2CX-738M-MC7W PyJWT accepts public JWK containers as HMAC secrets

Summary PyJWT 2.13.0 contains an incomplete defense against algorithm confusion when an application mixes symmetric and asymmetric algorithms in one verification path. A public RSA, EC, or OKP JWK can be accepted as an HMAC secret when it is wrapped in a JWKS object, nested in an array, or...

GHSA-9V7F-9G4P-FFGJ PyJWT: PyJWKClient follows redirects when fetching JWKS

Summary PyJWT 2.13.0 PyJWKClient followed HTTP redirects while fetching a JWKS, without validating the redirect destination. A configured trusted endpoint could therefore redirect the client to a different host. Impact When an application uses PyJWKClient with caller-supplied request headers and ...

PyJWT: PyJWKClient follows redirects when fetching JWKS

Summary PyJWT 2.13.0 PyJWKClient followed HTTP redirects while fetching a JWKS, without validating the redirect destination. A configured trusted endpoint could therefore redirect the client to a different host. Impact When an application uses PyJWKClient with caller-supplied request headers and ...

GHSA-P4G4-X82P-Q773 PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard

Summary HMACAlgorithm.preparekey blocks asymmetric keys from being used as HMAC secrets by searching for text markers only. It looks for -----BEGIN and for an ssh- prefix. The same key in DER form is binary ASN.1 and has neither marker, so it passes the check and is used as an HMAC secret. An...

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

Summary HMACAlgorithm.preparekey blocks asymmetric keys from being used as HMAC secrets by searching for text markers only. It looks for -----BEGIN and for an ssh- prefix. The same key in DER form is binary ASN.1 and has neither marker, so it passes the check and is used as an HMAC secret. An...

GHSA-R6X4-923Q-G947 PyJWT BOM Bypass

Affected Package - Package: PyJWT pyjwt on PyPI - Repository: https://www.google.com/url?q=https://github.com/jpadilla/pyjwt&source=gmail&ust=1781794518474000&sa=E - Affected version: 2.13.0 - Vulnerability class: Algorithm confusion / patch bypass --- Root Cause PyJWT 2.13.0 introduced a guard i...

PyJWT BOM Bypass

Affected Package - Package: PyJWT pyjwt on PyPI - Repository: https://www.google.com/url?q=https://github.com/jpadilla/pyjwt&source=gmail&ust=1781794518474000&sa=E - Affected version: 2.13.0 - Vulnerability class: Algorithm confusion / patch bypass --- Root Cause PyJWT 2.13.0 introduced a guard i...

GHSA-2GX3-RCP4-G85Q PyJWT: PyJWKClient still amplifies unauthenticated JWKS fetches on unknown kid values (incomplete fix of CVE-2026-48524)

Summary CVE-2026-48524 GHSA-fhv5-28vv-h8m8, "PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values DoS" was fixed in 2.13.0 by stopping fetchdata from clearing the cache on a fetch error. That closed one amplification path but did not add the mitigation the advisory's...

PyJWT: PyJWKClient still amplifies unauthenticated JWKS fetches on unknown kid values (incomplete fix of CVE-2026-48524)

Summary CVE-2026-48524 GHSA-fhv5-28vv-h8m8, "PyJWKClient unbounded JWKS endpoint requests via attacker-controlled kid values DoS" was fixed in 2.13.0 by stopping fetchdata from clearing the cache on a fetch error. That closed one amplification path but did not add the mitigation the advisory's...

EUVD-2026-88542

PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set...

PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set

Summary A malformed RSA JWK inside a JWK Set aborts parsing of the entire set instead of being skipped, because RSAAlgorithm.fromjwk can raise a plain ValueError that isn't caught by PyJWKSet's per-key error-skipping logic. Affected component / version - Package: PyJWT PyPI, ecosystem pip - Files...

GHSA-W6J9-CWV2-H6WQ PyJWT: Malformed RSA JWK aborts parsing of an entire JWK Set

Summary A malformed RSA JWK inside a JWK Set aborts parsing of the entire set instead of being skipped, because RSAAlgorithm.fromjwk can raise a plain ValueError that isn't caught by PyJWKSet's per-key error-skipping logic. Affected component / version - Package: PyJWT PyPI, ecosystem pip - Files...

Linux Distros Unpatched Vulnerability : CVE-2026-102273

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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...

Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : PyJWT vulnerabilities (USN-8823-1)

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8823-1 advisory. It was discovered that PyJWT incorrectly handled certain URIs when using PyJWKClient. A remot...

Improper Verification of Cryptographic Signature

Overview PyJWT is a Python implementation of RFC 7519. Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via the preparekey method in jwt/algorithms.py, where a public JWK container such as a JWK Set with a kty member nested inside a JSON array o...

Improper Verification of Cryptographic Signature

Overview PyJWT is a Python implementation of RFC 7519. Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via the preparekey method in jwt/algorithms.py, where an encoded JWK such as an RSA public key is accepted as a valid HMAC secret without...

Improper Handling of Exceptional Conditions

Overview PyJWT is a Python implementation of RFC 7519. Affected versions of this package are vulnerable to Improper Handling of Exceptional Conditions via the PyJWK constructor in jwt/apijwk.py when processing a JWK set containing a malformed key. An attacker who can supply a JWK set with a...

Improper Verification of Cryptographic Signature

Overview PyJWT is a Python implementation of RFC 7519. Affected versions of this package are vulnerable to Improper Verification of Cryptographic Signature via the fromjwk function in jwt/algorithms.py when loading an OKP Octet Key Pair private key from a JWK. The function constructs the private...