Path Traversal in pnpm (CVE-2026-59196)
Summary
Path traversal in pnpm (CVE-2026-59196). Data can be tampered with by attackers. Exploitable via node_modules. Mitigation: upgrade to 11.7.0 or later.
Original description
The description as published by the source.
Summary
The hoisted dependency alias issue tracked as GHSA-fr4h-3cph-29xv / CAND-PNPM-059 has been addressed in both pnpm and pacquet.
A crafted lockfile alias could be joined directly under a hoisted node_modules directory. Traversal aliases could escape that directory, while reserved aliases such as .bin or .pnpm could overwrite pnpm-owned layout. This patch validates package-name semantics and path containment before graph insertion or filesystem work.
Security boundary
- The TypeScript hoisted graph uses the shared safe join helper at the actual
dep.namesink. - The helper rejects traversal, absolute, platform-specific, and reserved package names.
- Pacquet validates the hoister's
dep.0.namebefore adding the graph node or recursing. - Both implementations return
ERR_PNPM_INVALID_DEPENDENCY_NAME. - Pacquet uses the same dependency-name containment rule at its hoisted graph sink as it uses for direct dependency aliases.
Exploit replay
Before the patch, a traversal alias in a hoisted lockfile imported package files outside the intended install root. With this patch, both pnpm and pacquet reject the alias before graph insertion or filesystem work, and the escaped file is not created.
Files changed
fs/symlink-dependency/src/safeJoinModulesDir.tsprovides the TypeScript containment helper.installing/deps-restorer/src/lockfileToHoistedDepGraph.tsvalidates the parsed dependency name at the hoisted graph sink.- `pacquet/crates/package-ma…
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-2026-59196 has been found in pnpm.
Attackers can target a specific entry point like node_modules over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 7.1/10.
What to do: upgrade pnpm to 11.7.0 or later.
If unsure, ask your IT team or search "pnpm CVE-2026-59196" on the vendor's site.
CVE-2026-59196 (pnpm) — CWE-22 / CVSS v3 7.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: node_modules / dep.name / dep.0.name / ERR_PNPM_INVALID_DEPENDENCY_NAME
Patched: 11.7.0 — 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 node_modules without authentication.
Check the vendor advisory for the affected versions of pnpm. Attack surface: node_modules / dep.name / dep.0.name / ERR_PNPM_INVALID_DEPENDENCY_NAME.
Severity: High (CVSS 7.1/10). Data can be tampered with by attackers.
Update to 11.7.0.
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 11.7.0ステージング環境で 11.7.0 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
- package github.com
- web github.com