Auth bypass in Semaphoreui Semaphore
CVE-2026-91994
Semaphore UI through 2.19.12 exempts GET and HEAD requests from project resource permission checks in GetMustCanMiddleware. Attackers with guest or task_runner roles can read all project environments including plaintext secrets, credentials, and passwords via GET requests to the environment endpoint.
Vulnerability class: Broken Access Control
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
Weakness classification (CWE)
References
- disclosure@vulncheck.com (issue-tracking, exploit)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (technical-description)
- disclosure@vulncheck.com (product)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91994?
- CVE-2026-91994 is a medium-severity vulnerability in Semaphoreui Semaphore, classified under Missing Authorization. CVSS score: 6.5/10. Published 2026-09-15.
- How severe is CVE-2026-91994?
- Medium severity. CVSS v3 base score is 6.5 out of 10.