Executive brief
Semaphore UI is an orchestration and workflow automation platform. This vulnerability allows an attacker to silently change any user's password—including administrators—by tricking them into visiting a malicious website while logged into Semaphore. With no additional security checks required, an attacker can gain full administrative control of the entire Semaphore instance, leading to potential data theft, system compromise, and operational disruption.
Technical details
This is a classic Cross-Site Request Forgery (CSRF) vulnerability combined with unverified password change (CWE-352, CWE-620). The /api/users/{id}/password endpoint fails to implement CSRF protection—no anti-CSRF token is validated, no current password confirmation is required, and the session cookie lacks SameSite attribute enforcement. An attacker can craft a malicious web page containing a hidden form that automatically submits a POST request to change the password when visited by an authenticated user. The attack requires only that the victim be logged into Semaphore in the same browser and visit the attacker-controlled page; no user interaction beyond clicking a link is needed. A working proof-of-concept demonstrates silent password changes via form submission with text/plain encoding to bypass same-origin policy restrictions. The vulnerability is exploitable remotely and affects all versions prior to commit c59c3dc9035b.
Affected products
- semaphoreui semaphore < 0.0.0-20260707190631-c59c3dc9035b, including 2.18.20
Timeline
- 2026-09-03: disclosed: Vulnerability disclosed via GitHub Advisory GHSA-8cj9-r88m-8945 and CVE-2026-73292
- 2026-07-07: patched: Fixed in commit c59c3dc9035b, released in v2.18.21
- 2026-08-12: advisory: Published to National Vulnerability Database