CVE-2026-55494

CRITICAL
Published Sep 30, 2026 Modified Sep 30, 2026 CWE-284

Description

Tugtainer is a self-hosted app for automating updates of Docker containers. Prior to version 1.30.4, Tugtainer Agent allows unauthenticated access to Docker management APIs when AGENT_SECRET is not configured. The Agent uses request signatures to protect its API routes. However, in agent/auth.py, the signature verification function returns successfully if Config.AGENT_SECRET is empty. This causes protected Agent APIs to become accessible without authentication. This issue has been patched in version 1.30.4.

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CVSS v3.1 Score

9.8
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0064
Probability of exploitation
0.50%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-284 CWE-284

References

Frequently Asked Questions

What is CVE-2026-55494? +
Tugtainer is a self-hosted app for automating updates of Docker containers. Prior to version 1.30.4, Tugtainer Agent allows unauthenticated access to Docker management APIs when AGENT_SECRET is not configured. The Agent uses request signatures to protect its API routes. However, in agent/auth.py, the signature verification function returns successfully if Config.AGENT_SECRET is empty. This causes protected Agent APIs to become accessible without authentication. This issue has been patched in version 1.30.4. It has a CVSS v3.1 base score of 9.8 (CRITICAL).
How severe is CVE-2026-55494? +
CVE-2026-55494 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0064, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-55494? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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