High severity · published Sep 30, 2026
CVE-2026-87004
Tugtainer: OIDC id_token claims accepted without signature/audience/expiry verification
8.1
CVSS
0.3%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 27% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
TU
tugtainer · Quenary
< 1.31.3 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-87004
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-87004
x_refsource_CONFIRM
https://github.com/Quenary/tugtainer/security/advisories/GHSA-crjc-6vc7-xrfh
x_refsource_MISC
https://github.com/Quenary/tugtainer/commit/b55269b6a3bfd43b0f2f5bd5f137ee0c81b7c2e4
x_refsource_MISC
https://github.com/Quenary/tugtainer/releases/tag/v1.31.3
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