CVE-2026-73294: Semaphoreui Semaphore

Critical severity, CVSS 9.9. EPSS: 0.7% chance of exploitation in the next 30 days.

Semaphore UI is a web interface for managing DevOps tools. Prior to 2.18.17 and 2.19.5-beta2, repository git_url handling passes an attacker-controlled --upload-pack option to CmdGitClient.GetLastRemoteCommitHash through POST /api/project/{id}/repositories and scheduled commit-hash polling, allowing a project Manager or Owner to execute arbitrary OS commands in the Semaphore server process. This issue is fixed in versions 2.18.17 and 2.19.5-beta2.

Affected products

• Semaphoreui Semaphore: before 2.18.17 (fixed in 2.18.17); from 2.19.0-alpha3, before 2.19.5-beta2 (fixed in 2.19.5-beta2)

Published 2026-08-12. Last modified 2026-09-09.