Path Traversal in pnpm (CVE-2026-50015)
Summary
Path traversal in pnpm (CVE-2026-50015). Data can be tampered with by attackers. Exploitable via patchedDependencies. Mitigation: upgrade to 11.4.0 or later.
Original description
The description as published by the source.
Summary
pnpm's patch application pipeline (@pnpm/patch-package) performs no path validation on file paths extracted from .patch files. An attacker who contributes a malicious patch file via a pull request can write attacker-controlled content to or delete arbitrary files on the filesystem during pnpm install, as the user running the install. The diff --git header paths containing ../../ sequences traverse out of the package directory, and the traversal is difficult to catch in code review because patch file diff headers are opaque to most reviewers.
Vulnerability Details
During pnpm install, when a patchedDependencies entry is present in pnpm-workspace.yaml, pnpm reads the referenced .patch file and applies it via the embedded @pnpm/patch-package library. The applyPatchToDir function at patching/apply-patch/src/index.ts:12-13 calls process.chdir(opts.patchedDir), setting the working directory to the installed package location deep inside node_modules/.pnpm/.
The patch parser at @pnpm/patch-package/dist/patch/parse.js:88 extracts file paths from diff --git a/(.*?) b/(.*?) headers using a regex with no path sanitization. The executeEffects function in apply.js then operates on these unsanitized paths:
File write (apply.js:35-49):
case 'file creation': {
const eff = effect
fs.ensureDirSync(dirname(eff.path))
fs.writeFileSync(eff.path, fileContents, { mode: eff.mode })
break
}
File delete (`apply.…
Source: GitHub Security Advisories (Global) 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-2026-50015 has been found in pnpm.
Attackers can target a specific entry point like patchedDependencies over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.3/10.
What to do: upgrade pnpm to 11.4.0 or later.
If unsure, ask your IT team or search "pnpm CVE-2026-50015" on the vendor's site.
CVE-2026-50015 (pnpm) — CWE-22 / CVSS v3 7.3
Attack vector: remote (network-reachable)
Attack surface: patchedDependencies / applyPatchToDir / executeEffects / apply.js
Patched: 11.4.0 — 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.
Path traversal (CWE-22) exists in pnpm. Attackers reach the vulnerable code path via patchedDependencies.
Check the vendor advisory for the affected versions of pnpm. Attack surface: patchedDependencies / applyPatchToDir / executeEffects / apply.js.
Severity: High (CVSS 7.3/10). Data can be tampered with by attackers.
Update to 11.4.0.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'pnpm' . 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
-
1Identify exposure identify
grep -r 'pnpm' . | 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
pnpmを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade pnpm to 11.4.0ステージング環境で 11.4.0 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を含めること。
-
3Post-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。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com