CVE-2026-62995
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. in versions 1.7.
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Publicado: 29 jul 2026 · Última mod.: 24 oct 2026 · CWE-345
0.1%EPSS · 30 días0.1%
2026-09-302026-10-28
joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. in versions 1.7.1 and prior, joserfc accepts JWTs with trailing padding (==) which are not conforming to the JOSE specifications. This leads to malleability of the JWTs when consumed by joserfc. Depending on this application this might or not be an issue. This could lead to bypass of token revocation or anti-replay protection when implemented as a deny list of tokens or a deny list of token hashes. Note that ECDSA JWS are always malleable because of the malleability of ECDSA signatures (first test case in the code bellow). This makes a scheme which assumes that JWTs are not malleable brittle. However for other signatures (or MAC) schemes it might make sense to assume non malleability of the token. This issue has been fixed in version 1.7.2.
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CVE-2026-110985——
——0A Kafka broker using SASL/OAUTHBEARER with the default validator (sasl.oauthbearer.jwt.validator.class=DefaultJwtValidator) selects its implementation from configuration. When sasl.oauthbearer.jwks.endpoint.url is set, the validator verifies the JWT signature. When that URL is unset (the default) and no verification key resolver is supplied, DefaultJwtValidator silently falls back to ClientJwtValidator, which does not verify the JWT signature, algorithm, or issuer - and the broker starts with no warning or error. This is the residual of CVE-2026-33557, whose fix restored signature verification only on the path where the JWKS endpoint URL is set.
Impact:
A broker in this state accepts any structurally valid JWT, including "alg":"none" tokens. An unauthenticated remote attacker who can reach the listener can forge a token asserting any principal - including configured superusers - and gain full access to the cluster. Only brokers that enable SASL/OAUTHBEARER validation without a JWKS endpoint URL (and without a custom verification key resolver) are affected; brokers that set the URL verify signatures and are not affected. Unlike CVE-2026-110952 (issuer/audience not enforced by default), here no signature is verified at all.
Mitigation (all affected versions, no upgrade required):
Set sasl.oauthbearer.jwks.endpoint.url for every listener/mechanism that uses OAuthBearerValidatorCallbackHandler, or configure a signature-verifying sasl.oauthbearer.jwt.validator.class.
Resolution:
From Apache Kafka 4.2.2, 4.3.1, and 4.4.0: a broker that would fall back to the non-verifying ClientJwtValidator fails to start with a ConfigException instead of running without signature verification (secure by default).21hCVE-2026-110952——
——0A Kafka broker that authenticates clients with SASL/OAUTHBEARER using the bundled JWKS-backed validator always verifies the JWT signature, but two further checks are only performed when explicitly configured:
- The issuer (iss) claim is verified only when sasl.oauthbearer.expected.issuer is set. When it is unset, a validly-signed token carrying the expected audience is accepted regardless of which issuer minted it.
- An audience (aud) claim is required only when sasl.oauthbearer.expected.audience is set. When it is unset, a validly-signed token that omits the aud claim is accepted. (A token that carries an aud claim is
still rejected when no expected audience is configured.)
Both options default to unset and have been documented as optional (Importance LOW) since KIP-768 (3.1.0).
Impact:
The exposure is realizable mainly in deployments whose JWKS endpoint serves signing keys for more than one issuer (a multi-tenant identity provider, an aggregated/shared JWKS, or shared signing keys): a token
minted for a different issuer, or a token lacking an audience, may be accepted to authenticate — potentially as a higher-privileged principal. In a single-issuer deployment where the provider controls the iss
claim and issues audience-scoped tokens, exposure is limited. The signature trust anchor remains enforced in all cases. This is distinct from CVE-2026-33557 (acceptance of unsigned/unvalidated tokens); here the
signature is validated and only the issuer/audience checks are not enforced by default.
Mitigation (all affected versions, no upgrade required):
Set both sasl.oauthbearer.expected.issuer (to your provider's exact iss value) and sasl.oauthbearer.expected.audience (to the audience(s) your brokers expect), per listener. Brokers that set these perform
exact-match issuer/audience checks and are not affected. Both have been available since 3.1.0.
Resolution:
- From Apache Kafka 4.4.0: a broker configured with a JWKS endpoint fails to start unless both sasl.oauthbearer.expected.issuer and sasl.oauthbearer.expected.audience are set (secure by default). Deployments that
intentionally do not restrict the issuer and/or audience may opt out per axis with sasl.oauthbearer.allow.unverified.issuer=true and/or sasl.oauthbearer.allow.unverified.audience=true.21hCVE-2026-1034028.8 ALT—
——0An Insufficient Verification of Data Authenticity vulnerability in PCLI in Juniper Networks Session Smart Router and Session Smart Conductor allows an attacker with write access to the model cache directory to execute arbitrary code and escalate privileges via the processing of unverified cache files.21hCVE-2026-1033305.3 MED—
——0The Sadad QA Payment WordPress plugin through 1.28 does not correctly verify the authenticity of incoming payment notifications, as the verification is keyed on a merchant secret that is empty by default and the rest of the signed data is attacker-controlled, allowing unauthenticated attackers to forge a valid confirmation and mark orders as paid without payment.20hCVE-2026-1033135.3 MED—
——0The BitPay Gateway for WooCommerce WordPress plugin through 4.1.3 does not bind the payment provider's transaction confirmation to the order it completes, nor verify the confirmed amount, allowing an unauthenticated attacker who holds a single genuine low-value transaction to mark arbitrary higher-value orders as paid.20hCVE-2026-1183777.5 ALT7.5%
——2mews/pos through 2.0.0 contains an insufficient verification of data authenticity vulnerability that allows unauthenticated attackers to forge payment results by submitting unverified callbacks. GarantiPos, PayForPos and InterPos 3D Pay and 3D Host handlers skip check3DHash(), letting attackers post tampered status, amount or order ID fields to complete orders without paying.22h