← Back
CVE-2026-46420
medium
CVSS 5.6
OS Command Injection in shivammathur/setup-php (CVE-2026-46420)
Summary
OS command injection in shivammathur/setup-php (CVE-2026-46420). Risk of unauthorized operations or information disclosure. Exploitable via ``composer.lock``. Mitigation: upgrade to `2.37.1` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-46420** has been found in shivammathur/setup-php.
Attackers can target a specific entry point like ``composer.lock`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.6/10.
What to do: upgrade shivammathur/setup-php to **2.37.1** or later.
If unsure, ask your IT team or search "shivammathur/setup-php CVE-2026-46420" on the vendor's site.
CVE-2026-46420 (shivammathur/setup-php) — CWE-78 / CVSS v3 5.6
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `composer.lock` / `config.platform.php` / `pull_request_target`
Patched: `2.37.1` — 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 shivammathur/setup-php. Attackers reach the vulnerable code path via ``composer.lock`` without authentication.
📍 Affected scope
shivammathur/setup-php — . Attack surface: `composer.lock` / `config.platform.php` / `pull_request_target`.
🔥 Severity
Severity: Medium (CVSS 5.6/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **2.37.1**.
🛡️ 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 request patterns matching this CVE's known IOCs. Run `grep -r 'shivammathur/setup-php' .` against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'shivammathur/setup-php' . | 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 `shivammathur/setup-php` を grep し、稼働しているサービス・バージョンを把握する。
-
6Apply patch patch
Upgrade shivammathur/setup-php to 2.37.1ステージング環境で 2.37.1 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 3 で見つけた異常検知の続報チェックを含めること。
-
7Post-deployment verification verify
Confirm patched version is live in production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 3 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
actions
shivammathur/setup-php
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.37.1"}]}]
GitHub Actions
shivammathur/setup-php
[{"type":"ECOSYSTEM","events":[{"introduced":"2.25.0"},{"fixed":"2.37.1"}]}]