---
title: "CVE-2026-73294: Semaphore U: OS Command Injection"
url: https://erroneo.us/security/cve/CVE-2026-73294/
description: "CVE-2026-73294 (github.com/semaphoreui/semaphore (Go)): Semaphore UI is a web interface for managing DevOps tools. Prior to 2.18.17 and 2.19.5-beta2…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-08-12
date_modified: 2026-09-08
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-73294"
kev: false
cvss: 9.9
epss: 0.0065
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-73294: Semaphore U: OS Command Injection

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.7% , percentile 50: FIRST’s model estimates a 0.7% chance of exploitation activity in the next 30 days, higher than 50% of all scored CVEs (moderate). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/semaphoreui/semaphore (Go) < 0.0.0-20260704181911-7e8a9434bd81, fixed in 0.0.0-20260704181911-7e8a9434bd81 . Check your lockfile, including transitive dependencies.

## What it is

Semaphore UI is a web interface for managing DevOps tools. Prior to 2.18.17 and 2.19.5-beta2, repository giturl 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

- Go `github.com/semaphoreui/semaphore` < 0.0.0-20260704181911-7e8a9434bd81 → fixed: 0.0.0-20260704181911-7e8a9434bd81

## Affected products (CVE record)

- semaphoreui semaphore: < 2.18.17, >= 2.19.0-alpha3, < 2.19.5-beta2

## Severity

- GitHub_M CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.65% probability of exploitation activity in the next 30 days; percentile 50.

## Sources

- [GitHub Advisory GHSA-xp7j-h7jc-4w8p](https://github.com/advisories/GHSA-xp7j-h7jc-4w8p)
- [CVE.org record CVE-2026-73294](https://www.cve.org/CVERecord?id=CVE-2026-73294)
- [NVD entry CVE-2026-73294](https://nvd.nist.gov/vuln/detail/CVE-2026-73294)
- [github.com](https://github.com/semaphoreui/semaphore/security/advisories/GHSA-xp7j-h7jc-4w8p)
- [github.com](https://github.com/semaphoreui/semaphore/commit/7e8a9434bd81b82cf42220151c74801ea97542d6)
- [github.com](https://github.com/semaphoreui/semaphore/commit/a7a7a33a64aea382a0726b3722856f298663eacf)
- [github.com](https://github.com/semaphoreui/semaphore/tree/v2.18.17)
- [github.com](https://github.com/semaphoreui/semaphore/tree/v2.19.5-beta2)

---
Source page: https://erroneo.us/security/cve/CVE-2026-73294/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt