---
title: "CVE-2026-87004: Tugtainer - Authentication Bypass"
description: "Tugtainer < 1.31.3 contains an authentication bypass caused by improper OIDC id_token validation in auth_oidc_provider.py, letting attackers bypass token verification and impersonate users, exploit requires valid OIDC login flow completion."
url: https://panop.io/threat-heartbeat/CVE-2026-87004/
---

# CVE-2026-87004 Tugtainer - Authentication Bypass

Tugtainer < 1.31.3 contains an authentication bypass caused by improper OIDC id\_token validation in auth\_oidc\_provider.py, letting attackers bypass token verification and impersonate users, exploit requires valid OIDC login flow completion.

CVSS base score 8.1 /10

High

CISA KEV

Not listed

Public exploit

Proof of concept available

Authentication

Not required

EPSS

0.34% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-87004)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Published

30 September 2026

Updated

15 October 2026

Weakness

[CWE-347](https://cwe.mitre.org/data/definitions/347.html)

## Vendor fix

Upgrade to version 1.31.3 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-87004](https://nvd.nist.gov/vuln/detail/CVE-2026-87004)
- [https://github.com/Quenary/tugtainer/commit/b55269b6a3bfd43b0f2f5bd5f137ee0c81b7c2e4](https://github.com/Quenary/tugtainer/commit/b55269b6a3bfd43b0f2f5bd5f137ee0c81b7c2e4)
- [https://github.com/Quenary/tugtainer/releases/tag/v1.31.3](https://github.com/Quenary/tugtainer/releases/tag/v1.31.3)
- [https://github.com/Quenary/tugtainer/security/advisories/GHSA-crjc-6vc7-xrfh](https://github.com/Quenary/tugtainer/security/advisories/GHSA-crjc-6vc7-xrfh)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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