python-pyjwt: PyJWT: Authentication bypass due to forged JSON Web Tokens

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...

Fulcio has OIDC Discovery Redirect Following Allows SSRF and JWKS Substitution for Meta-Issuer Paths, with Kubernetes Service-Account Token Leakage

Impact Three security vulnerabilities were identified in the OIDC Discovery client: 1. Blind Server-Side Request Forgery SSRF via Cross-Host Redirects: Fulcio uses an HTTP client to fetch OIDC discovery metadata /.well-known/openid-configuration. Prior to this fix, if a configured issuer returned...

Authlib JWS JWK Header Injection: Signature Verification Bypass

Description SummaryA JWK Header Injection vulnerability in authlib's JWS implementation allows an unauthenticatedattacker to forge arbitrary JWT tokens that pass signature verification. When key=None is passedto any JWS deserialization function, the library extracts and uses the cryptographic key...

PYSEC-2026-287 Authlib JWS JWK Header Injection: Signature Verification Bypass

Description Summary A JWK Header Injection vulnerability in authlib's JWS implementation allows an unauthenticated attacker to forge arbitrary JWT tokens that pass signature verification. When key=None is passed to any JWS deserialization function, the library extracts and uses the cryptographic...

PT-2026-53761

Name of the Vulnerable Software and Affected Versions Open Access Management OpenAM versions prior to 16.1.1 Description An improper authentication issue exists in the private key jwt client authentication path. The system uses ClientJwksResolverCache without reliably binding a cached jwks uri...

GHSA-H5RG-8P7F-47G2 SurrealDB: SSRF via JWKS URL — Redirect Following in JWT Key Fetch

SurrealDB fetches the JWKS document for a JWT or record access method using a bare reqwest client that follows HTTP redirects by default. The network capability check in core/src/iam/jwks.rs checkcapabilitiesurl is applied only to the originally configured URL; redirect targets are not...

SurrealDB: SSRF via JWKS URL — Redirect Following in JWT Key Fetch

SurrealDB fetches the JWKS document for a JWT or record access method using a bare reqwest client that follows HTTP redirects by default. The network capability check in core/src/iam/jwks.rs checkcapabilitiesurl is applied only to the originally configured URL; redirect targets are not...

Exposure of Resource to Wrong Sphere

Overview Affected versions of this package are vulnerable to Exposure of Resource to Wrong Sphere in the TokenKeyResolver function. An attacker can bypass authentication and gain unauthorized access by exploiting the shared static JWKS cache across multiple schemes, allowing a key fetched for one...

CVE-2026-50202 Steeltoe's static JWKS cache shared across schemes and never invalidated

Steeltoe is an open source project that provides a collection of libraries that helps users build cloud-native applications. In Steeltoe.Security.Authentication.CloudFoundryBase prior to version 3.4.0, Steeltoe.Security.Authentication.JwtBearer prior to version 4.2.0, and...

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...

python-pyjwt: PyJWT: Denial of Service via unverified JSON Web Token key IDs

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-2026-48526

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-2026-48523

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...

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...

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...

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...