GHSA-PXH4-856F-4H89 PyJWT: HS256/384/512 verify accepts empty HMAC key via oct JWK (PyJWK/PyJWKClient) enabling token forgery

Summary HMACAlgorithm.fromjwk accepts a symmetric kty=oct JWK whose k value is the empty string and returns a zero-length key without raising. When a token is then verified with that key object a PyJWK, or a PyJWK resolved by PyJWKSet / PyJWKClient, the HMAC verifier computes HMACkey=b"",...

PyJWT: HS256/384/512 verify accepts empty HMAC key via oct JWK (PyJWK/PyJWKClient) enabling token forgery

Summary HMACAlgorithm.fromjwk accepts a symmetric kty=oct JWK whose k value is the empty string and returns a zero-length key without raising. When a token is then verified with that key object a PyJWK, or a PyJWK resolved by PyJWKSet / PyJWKClient, the HMAC verifier computes HMACkey=b"",...

pyjwt: pyjwt: Verification key substitution via unvalidated JWKS redirects

A flaw was found in PyJWT. When retrieving cryptographic keys from a JSON Web Key Set JWKS endpoint, PyJWKClient fails to validate HTTP redirect destinations against trusted domain boundaries. A remote attacker who can influence the response of a trusted endpoint can redirect key requests to an...

OESA-2026-4387 python-jwt security update

setup.py test %endif Security Fixes: PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not revalidated against the JWKS trust boundary. This occurs when a configured trusted JWKS endpoint returns an...

OESA-2026-4386 python-jwt security update

setup.py test %endif Security Fixes: PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not revalidated against the JWKS trust boundary. This occurs when a configured trusted JWKS endpoint returns an...

OESA-2026-4384 python-jwt security update

setup.py test %endif Security Fixes: PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not revalidated against the JWKS trust boundary. This occurs when a configured trusted JWKS endpoint returns an...

OESA-2026-4385 python-jwt security update

setup.py test %endif Security Fixes: PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not revalidated against the JWKS trust boundary. This occurs when a configured trusted JWKS endpoint returns an...

PYSEC-2026-4140 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...

PYSEC-2026-4144 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 still amplifies unauthenticated JWKS fetches on unknown kid values (incomplete fix of CVE-2026-48524)

SummaryCVE-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 tit...

PyJWT: PyJWKClient follows redirects when fetching JWKS

SummaryPyJWT 2.13.0 PyJWKClient followed HTTP redirects while fetching a JWKS,without validating the redirect destination. A configured trusted endpointcould therefore redirect the client to a different host. ImpactWhen an application uses PyJWKClient with caller-supplied request headers andan...

PT-2026-105891

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 ...

PT-2026-105889

Summary PyJWKClient.get signing key from jwttoken — the first step of the JWKS verification flow documented in docs/usage.rst — must decode a token's payload before its signature can be checked, via jwt.api jwt.decode completetoken, options="verify signature": False. That call parses the payload...

PyJWT: Unauthenticated RecursionError DoS in pre-verification payload parse (PyJWKClient.get_signing_key_from_jwt / verify_signature=False)

Summary PyJWKClient.getsigningkeyfromjwttoken — the first step of the JWKS verification flow documented in docs/usage.rst — must decode a token's payload before its signature can be checked, via jwt.apijwt.decodecompletetoken, options="verifysignature": False. That call parses the payload with...

Linux Distros Unpatched Vulnerability : CVE-2026-102267

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. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not revalidated...

Linux Distros Unpatched Vulnerability : CVE-2026-101918

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 2.0.0a1 until 2.15.0, PyJWT PyJWKClient.getsigningkeyfromjwt is affected because payload pars...

SUSE CVE-2026-102267

PyJWT is a Python implementation of JSON Web Token standards. Prior to 2.14.0, PyJWT PyJWKClient is affected because redirect destinations are not revalidated against the JWKS trust boundary. This occurs when a configured trusted JWKS endpoint returns an attacker-influenced redirect. As a result,...

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-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...