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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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"",...

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: 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...

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...