CVE-2025-55299: VaulTLS has a password-based login exploit in additional user accounts

Severity: critical (CVSS 9.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-18 · updated 2026-06-17
Weakness: CWE-521

Description

VaulTLS is a modern solution for managing mTLS (mutual TLS) certificates. Prior to 0.9.1, user accounts created through the User web UI have an empty but not NULL password set, attackers can use this to login with an empty password. This is combined with that fact, that previously disabling the password based login only effected the frontend, but still allowed login via the API. This vulnerability is fixed in 0.9.1.

Affected products

7ritn VaulTLS: before 0.9.1

References

https://github.com/7ritn/VaulTLS/commit/6ac0a43a768f1753f6889ba43f914e773a4b45c0
https://github.com/7ritn/VaulTLS/security/advisories/GHSA-pjfr-pj3h-cw8m

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