PyJWT: Public-key JWK accepted as HMAC secret enables forged HS256 tokens when mixed families are allowed

!NOTE Exploitation requires a verifier configured with both symmetric and asymmetric algorithms in algorithms=… and a raw-JSON JWK as the key= argument, both contrary to documented usage, hence the High attack-complexity rating. Summary When the verifier is decoding JSON Web Tokens, while...

GHSA-XGMM-8J9V-C9WX PyJWT: Public-key JWK accepted as HMAC secret enables forged HS256 tokens when mixed families are allowed

!NOTE Exploitation requires a verifier configured with both symmetric and asymmetric algorithms in algorithms=… and a raw-JSON JWK as the key= argument, both contrary to documented usage, hence the High attack-complexity rating. Summary When the verifier is decoding JSON Web Tokens, while...

EUVD-2026-32918

PyJWT: Algorithm allow-list bypass when decoding with PyJWK / PyJWKClient keys...

CVE-2026-48526

A flaw was found in PyJWT, a Python library for JSON Web Token JWT implementation. When decoding JWTs, the library fails to validate the use of JSON Web Keys JWK in the HMAC algorithm while also supporting asymmetric algorithms. This allows a remote attacker to use the issuer's public key as the...

CVE-2026-48524

A flaw was found in PyJWT, a Python library for JSON Web Token JWT implementation. A remote attacker can exploit this vulnerability by sending specially crafted JWTs with unknown 'kid' key ID values. This can force the PyJWKClient.getsigningkey function to make an unlimited number of unrate-limit...

CVE-2026-48523

A flaw was found in PyJWT, a Python library for handling JSON Web Tokens JWT. An attacker with control over a registered JSON Web Key JWK private key can bypass security checks by signing a token with a forbidden algorithm while claiming to use an allowed one. This allows the attacker to have the...

Hono: JWT middleware accepts any Authorization scheme, not only Bearer

Summary The jwt and jwk middlewares do not verify that the Authorization header value uses theBearer scheme. Any two-part header value — regardless of the scheme name in the first position — proceeds to JWT verification. A request presenting a valid JWT under a non-Bearer scheme identifier such a...

GHSA-F577-QRJJ-4474 Hono: JWT middleware accepts any Authorization scheme, not only Bearer

Summary The jwt and jwk middlewares do not verify that the Authorization header value uses theBearer scheme. Any two-part header value — regardless of the scheme name in the first position — proceeds to JWT verification. A request presenting a valid JWT under a non-Bearer scheme identifier such a...

PT-2026-46859

Summary The jwt and jwk middlewares do not verify that the Authorization header value uses theBearer scheme. Any two-part header value — regardless of the scheme name in the first position — proceeds to JWT verification. A request presenting a valid JWT under a non-Bearer scheme identifier such a...

SUSE CVE-2026-48523

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode or jwt.decodecomplete are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature...

Unintended Proxy or Intermediary ('Confused Deputy')

Overview Affected versions of this package are vulnerable to Unintended Proxy or Intermediary 'Confused Deputy' via the uri parameter being passed directly to urllib.request.urlopen, which allows fetching resources using unsupported schemes such as file, ftp, and data. An attacker can access...

DEBIAN-CVE-2026-48526

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, when the verifier is decoding JSON Web Tokens, while supporting both asymmetric and HMAC algorithms, the library does not validate use of JSON Web Keys in HMAC algorithm, allowing attacker to use the issuer public key as the...

PYSEC-2026-176

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode or jwt.decodecomplete are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature...

PYSEC-2026-177

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.getsigningkey forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited...

PYSEC-2026-177

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.getsigningkey forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited...

PYSEC-0000-CVE-2026-48523

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode or jwt.decodecomplete are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature...

CVE-2026-48524

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, PyJWKClient.getsigningkey forces a fresh HTTP request to the JWKS endpoint for every JWT with an unknown kid value, with no rate limiting. Since kid comes from the unverified token header, an attacker can trigger unlimited...

CVE-2026-47673

CVE-2026-47673 concerns the Hono web framework. Before version 4.12.21, the jwt and jwk middlewares did not validate that the Authorization header used the Bearer scheme. Any two-part header value—regardless of the scheme name in the first position—proceeds to JWT verification. As a result, a req...

CVE-2026-48523

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode or jwt.decodecomplete are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature...

CVE-2026-48526

PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, when the verifier is decoding JSON Web Tokens, while supporting both asymmetric and HMAC algorithms, the library does not validate use of JSON Web Keys in HMAC algorithm, allowing attacker to use the issuer public key as the...