Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-73294 critical CVSS 9.9

OS Command Injection in github.com/semaphoreui/semaphore (CVE-2026-73294)

Summary

OS command injection in github.com/semaphoreui/semaphore (CVE-2026-73294). Successful exploitation can lead to full system takeover. Exploitable via POST /api/project/{id}/repositories. Mitigation: upgrade to 0.0.0-20260704181911-7e8a9434bd81 or later.

Original description

The description as published by the source.

Summary

An OS command injection in repository git_url handling lets any user holding the Manager or Owner role on any project (the normal project-collaborator roles) achieve remote code execution on the Semaphore server host. Using git's --upload-pack= option, an attacker runs arbitrary commands. The command executes inside the main Semaphore server process (via the schedule commit-hash poller), so it runs even when jobs are configured for remote runners — bypassing runner isolation and exposing the master encryption key and every project's secrets. Reproducible on a default install (git_client: cmd_git); no non-default configuration is required.

Details

The repository git_url is attacker-controlled (HTTP body) and reaches exec.Command("git", ...) unvalidated. Two missing controls cause this:

  1. git_url is never validated against option injection.
    Repository.Validate() (db/Repository.go, ~lines 138–156) validates the branch via ValidateGitBranch (db/git_branch.go, which rejects a leading -), but performs no equivalent check on GitURL (only "non-empty"). ValidateRepository (db/Store.go, ~802–806) only checks the SSH key. CreateRepository (db/sql/repository.go, ~76–95) stores it verbatim. Because --upload-pack=... has no scheme:// and no leading /, GetType() (db/Repository.go, ~113–136) classifies it as RepositorySSH and GetGitURL(false) (~72–111) returns it raw/unchanged.

  2. The git command is built with no -- separator.
    CmdGitClient.GetLastRemoteCommitHash (db_lib/CmdG…

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-73294 has been found in github.com/semaphoreui/semaphore.
Attackers can target a specific entry point like POST /api/project/{id}/repositories over the network to misuse the product.
Successful exploitation can lead to full system takeover. CVSS score: 9.9/10.
What to do: upgrade github.com/semaphoreui/semaphore to 0.0.0-20260704181911-7e8a9434bd81 or later.
If unsure, ask your IT team or search "github.com/semaphoreui/semaphore CVE-2026-73294" on the vendor's site.

CVE-2026-73294 (github.com/semaphoreui/semaphore) — CWE-78 / CVSS v3 9.9
Attack vector: remote (network-reachable) / no user interaction
Attack surface: POST /api/project/{id}/repositories / POST /api/project/{id}/schedules / post /api/project/
Patched: 0.0.0-20260704181911-7e8a9434bd81 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

OS command injection (CWE-78) exists in github.com/semaphoreui/semaphore. Attackers reach the vulnerable code path via POST /api/project/{id}/repositories.

📍 Affected scope

Check the vendor advisory for the affected versions of github.com/semaphoreui/semaphore. Attack surface: POST /api/project/{id}/repositories / POST /api/project/{id}/schedules / post /api/project/.

🔥 Severity

Severity: Critical (CVSS 9.9/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to 0.0.0-20260704181911-7e8a9434bd81.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual POST /api/project/{id}/repositories requests with malformed payloads or SQL meta-characters. Run grep -r 'github.com/semaphoreui/semaphore' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'github.com/semaphoreui/semaphore' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で github.com/semaphoreui/semaphore を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Hunt for indicators of compromise detect 
    grep 'POST /api/project/{id}/repositories' /var/log/nginx/access.log | grep -E '(unusual_payload|sqli_pattern)'

    アクセスログで POST /api/project/{id}/repositories への異常なリクエスト (不正な認証ヘッダ・SQLメタ文字)を過去 30〜90日分捜索。WAF/SIEM があれば該当パスのアラート発火履歴を確認。

  3. 3
    Apply patch patch 
    Upgrade github.com/semaphoreui/semaphore to 0.0.0-20260704181911-7e8a9434bd81

    ステージング環境で 0.0.0-20260704181911-7e8a9434bd81 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスと、Step 2 で見つけた異常検知の続報チェックを含めること。

  4. 4
    Post-deployment verification verify 
    Replay attack against POST /api/project/{id}/repositories on staging to confirm patch closes the vector

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番では Step 2 と同じログクエリでアラート再発が無いか継続監視。

Affected packages

go github.com/semaphoreui/semaphore
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.0.0-20260704181911-7e8a9434bd81"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details