CVE-2026-73294 semaphoreui CVE debrief

Who should care

Defenders responsible for managing DevOps tools, specifically those using Semaphore UI, should assess exposure and prioritize patching to versions 2.18.17 or 2.19.5-beta2. Project Managers and Owners using Semaphore UI should be aware of the vulnerability and take necessary actions to restrict access and monitor for suspicious activity.

Why it matters

The critical vulnerability in Semaphore UI requires immediate attention from defenders managing DevOps tools. The vulnerability allows project Managers and Owners to execute arbitrary OS commands, potentially disrupting DevOps tool management. Defenders should prioritize patching to versions 2.18.17 or 2.19.5-beta2, restrict access, and monitor for suspicious activity. The impact of the vulnerability is supported by the CVE record and NVD entry, but further verification is needed to determine the full scope of affected versions and exposure.

• Potential for arbitrary OS command execution in Semaphore server process
• Possible disruption of DevOps tool management
• Need for verification of affected versions and exposure
• Priority for patching and restricting access

Technical summary

The vulnerability in Semaphore UI allows a project Manager or Owner to execute arbitrary OS commands in the Semaphore server process through repository git_url handling. This is achieved by passing an attacker-controlled --upload-pack option to CmdGitClient.GetLastRemoteCommitHash via POST /api/project/{id}/repositories and scheduled commit-hash polling. The issue is fixed in versions 2.18.17 and 2.19.5-beta2.

Defensive priority

Defenders should prioritize patching Semaphore UI instances to versions 2.18.17 or 2.19.5-beta2 and restrict access to project Managers and Owners.

Recommended defensive actions

• Patch Semaphore UI instances to versions 2.18.17 or 2.19.5-beta2
• Restrict access to project Managers and Owners
• Monitor for suspicious activity on Semaphore UI instances
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its critical CVSS score of 9.9 and the affected versions of Semaphore UI. The Semaphore UI vulnerability allows project Managers and Owners to execute arbitrary OS commands. Evidence is limited to public CVE and NVD data. Defenders should verify Semaphore UI versions, review access controls, and monitor for suspicious activity related to git_url handling and commit-hash polling.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.