Semaphore U: OS Command Injection
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-78.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| semaphoreui | semaphore | before 2.18.17; 2.19.0-alpha3 to before 2.19.5-beta2 | 2.18.17, 2.19.5-beta2 | Patch available | CNA |
| — | github.com/semaphoreui/semaphore (Go) | before 0.0.0-20260704181911-7e8a9434bd81 | 0.0.0-20260704181911-7e8a9434bd81 | Patch available | GHSA-xp7j-h7jc-4w8p |
- semaphore Vendorsemaphoreui Affected before 2.18.17; 2.19.0-alpha3 to before 2.19.5-beta2 Fixed in 2.18.17, 2.19.5-beta2 Patch available CNA
- github.com/semaphoreui/semaphore (Go) Vendor— Affected before 0.0.0-20260704181911-7e8a9434bd81 Fixed in 0.0.0-20260704181911-7e8a9434bd81 Patch available GHSA-xp7j-h7jc-4w8p
Remediation
- Fix · CNA semaphore (semaphoreui) Fixed in 2.18.17, 2.19.5-beta2
- Fix · GHSA-xp7j-h7jc-4w8p github.com/semaphoreui/semaphore (Go) Fixed in 0.0.0-20260704181911-7e8a9434bd81 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-73294
- 2026-10-03 Alias added: GHSA-xp7j-h7jc-4w8p
- 2026-10-16 EPSS moved to the 50th–90th percentile
References
Other 6
- https://github.com/semaphoreui/semaphore/security/advisories/GHSA-xp7j-h7jc-4w8p
- https://github.com/semaphoreui/semaphore/commit/7e8a9434bd81b82cf42220151c74801ea97542d6
- https://github.com/semaphoreui/semaphore/commit/a7a7a33a64aea382a0726b3722856f298663eacf
- https://github.com/semaphoreui/semaphore/tree/v2.18.17
- https://github.com/semaphoreui/semaphore/tree/v2.19.5-beta2
- https://github.com/semaphoreui/semaphore
More semaphoreui vulnerabilities
- TI-2026-51418 Semaphore UI: Manager-to-owner privilege escalation via custom-role slug collision CVSS 3.1HIGH 8.8
- TI-2026-62124 Semaphore UI through 2.19.12 Missing Authorization on GET and HEAD Requests CVSS 4.0HIGH 7.1
- TI-2026-76499 Remote code execution in Semaphore UI via Ansible variable override CVSS 4.0HIGH 8.7
- TI-2026-51417 Semaphore UI: CSRF vulnerability on password change endpoint - No CSRF token or password confirmation CVSS 3.1HIGH 8.3
Sources
- CVE-2026-73294 · CVE Program
- CVE-2026-73294 · NVD
- FIRST EPSS
- GHSA-xp7j-h7jc-4w8p · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences