Quenary Tugtainer up to 1.31.2 OIDC Provider auth_oidc_provider.py jose.jwt.get_unverified_claims signature verification

Summaryinfo

A vulnerability, which was classified as critical, has been found in Quenary Tugtainer up to 1.31.2. This affects the function jose.jwt.get_unverified_claims of the file backend/modules/auth/providers/auth_oidc_provider.py of the component OIDC Provider. This manipulation causes signature verification. This vulnerability is registered as CVE-2026-87004. Remote exploitation of the attack is possible. No exploit is available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability was found in Quenary Tugtainer up to 1.31.2. It has been declared as critical. Affected by this vulnerability is the function jose.jwt.get_unverified_claims of the file backend/modules/auth/providers/auth_oidc_provider.py of the component OIDC Provider. The manipulation with an unknown input leads to a signature verification vulnerability. The CWE definition for the vulnerability is CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Tugtainer is a self-hosted app for automating updates of Docker containers. Prior to version 1.31.3, when the OIDC login flow completes, backend/modules/auth/providers/auth_oidc_provider.py decodes the id_token returned by the identity provider's token endpoint using jose.jwt.get_unverified_claims() instead of jwt.decode(). This skips signature verification, audience (aud) validation, issuer (iss) validation, and expiry (exp) checking entirely. The extracted claims (email/sub/preferred_username) are then used directly as the user_id for the resulting Tugtainer session. This issue has been patched in version 1.31.3.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-87004 since 09/08/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 1.31.3 eliminates this vulnerability.

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Productinfo

Vendor

• Quenary

Name

• Tugtainer

Version

• 1.31.0
• 1.31.1
• 1.31.2

Website

• Product: https://github.com/Quenary/tugtainer/

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