Path Traversal in pnpm (CVE-2026-55700)
Summary
Path traversal in pnpm (CVE-2026-55700). Data can be tampered with by attackers. Exploitable via main. Mitigation: upgrade to 11.5.3 or later.
Original description
The description as published by the source.
Summary
The staged-tarball filename traversal reported as GHSA-v23m-ccfg-pq9h / CAND-PNPM-038 is fixed on main by pnpm/pnpm#12303, merged as 65443f4bdf1f0db9c8c7dc58fee25252607e9234.
Before the fix, pnpm stage download derived a local filename from registry-controlled package name and version fields. A crafted manifest could escape the selected download directory and overwrite another reachable file. The merged fix validates both fields, derives one safe filename, and verifies the final destination before writing.
Security boundary
- Package names and semantic versions are validated before they can influence a local filename.
- POSIX and Windows path separators are rejected by basename checks.
- Stage download and tarball summary paths use the same filename helper.
- The resolved output path must remain an immediate child of the selected download directory.
- The stage identifier is already constrained to a UUID.
Exploit replay
Before 65443f4bdf, a traversal-bearing manifest version could make the command write outside the selected directory. After the fix, malicious package names fail with ERR_PNPM_INVALID_PACKAGE_NAME, malicious versions fail with ERR_PNPM_INVALID_PACKAGE_VERSION, no outside file is created, and the download directory remains empty.
Files changed
releasing/commands/src/tarball/safeTarballFilename.tsvalidates manifest identity and rejects cross-platform path separators.- `releas…
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-2026-55700 has been found in pnpm.
Attackers can target a specific entry point like main 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 11.5.3 or later.
If unsure, ask your IT team or search "pnpm CVE-2026-55700" on the vendor's site.
CVE-2026-55700 (pnpm) — CWE-22 / CVSS v3 7.1
Attack vector: remote (network-reachable) / unauthenticated
Attack surface: main / ERR_PNPM_INVALID_PACKAGE_NAME / ERR_PNPM_INVALID_PACKAGE_VERSION / pnpm
Patched: 11.5.3 — 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 main without authentication.
Check the vendor advisory for the affected versions of pnpm. Attack surface: main / ERR_PNPM_INVALID_PACKAGE_NAME / ERR_PNPM_INVALID_PACKAGE_VERSION / pnpm.
Severity: High (CVSS 7.1/10). Data can be tampered with by attackers.
Update to 11.5.3.
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 11.5.3ステージング環境で 11.5.3 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
- web github.com