Vulnerability · Published Aug 12, 2026 · Assigned by GitHub_M

CVE-2026-73294Semaphore U: OS Command Injection

Critical 9.9

In plain English

A critical-severity OS command injection in semaphore from semaphoreui. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.9Critical

Exploit odds (30 days)0.7%top 48.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/semaphoreui/semaphore	0.0.0-20260704181911-7e8a9434bd81	GHSA-xp7j-h7jc-4w8p
Go	github.com/semaphoreui/semaphore	0.0.0-20260704181911-7e8a9434bd81	GO-2026-6435

Affected products (as reported)

Vendor	Product	Versions
semaphoreui	semaphore	< 2.18.17>= 2.19.0-alpha3, < 2.19.5-beta2

Weakness: CWE-78, CWE-88 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

https://github.com/semaphoreui/semaphore/security/advisories/GHSA-xp7j-h7jc-4w8p x_refsource_CONFIRM
https://github.com/semaphoreui/semaphore/commit/7e8a9434bd81b82cf42220151c74801ea97542d6 x_refsource_MISC
https://github.com/semaphoreui/semaphore/commit/a7a7a33a64aea382a0726b3722856f298663eacf x_refsource_MISC
https://github.com/semaphoreui/semaphore/tree/v2.18.17 x_refsource_MISC
https://github.com/semaphoreui/semaphore/tree/v2.19.5-beta2 x_refsource_MISC