Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, 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 key embedded in the attacker-controlled JWT jwk header field. An attacker can sign a token with their own private key, embed the matching public key in the header, and have the server accept the forged token as cryptographically valid — bypassing authentication and authorization entirely. This issue has been patched in version 1.6.9.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 / openSUSE 15 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:0975-1 advisory.

    - CVE-2026-27962: JWS `deserialize_compact()` allows for signature bypass by accepting user-controlled     embedded JWK as       verification key (bsc#1259738).
    - CVE-2026-28490: cryptographic padding oracle in JWE RSA1_5 key management algorithm (bsc#1259736).
    - CVE-2026-28498: fail-open in behavior OIDC hash validation allows for bypass mandatory integrity     protections       (bsc#1259737).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, 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 key embedded in the attacker-controlled JWT jwk     header field. An attacker can sign a token with their own private key, embed the matching public key in     the header, and have the server accept the forged token as cryptographically valid  bypassing     authentication and authorization entirely. This issue has been patched in version 1.6.9. (CVE-2026-27962)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
303588	SUSE SLED15 / SLES15 / openSUSE 15 Security Update : python-Authlib (SUSE-SU-2026:0975-1)	Nessus	SuSE Local Security Checks	high
302533	Linux Distros Unpatched Vulnerability : CVE-2026-27962	Nessus	Misc.	critical

Detections

Analytics

CVE-2026-27962

critical

Tenable Plugins

high

critical