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CVE-2026-59871
medium
CVSS 5.3
Vulnerability in tar (CVE-2026-59871)
Summary
vulnerability in tar (CVE-2026-59871). Risk of unauthorized operations or information disclosure. Exploitable via ``pax.ts``. Mitigation: upgrade to `7.5.18` or later.
AI summary snake-internal / snake-material-v2
A vulnerability tracked as **CVE-2026-59871** has been found in tar.
Attackers can target a specific entry point like ``pax.ts`` over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 5.3/10.
What to do: upgrade tar to **7.5.18** or later.
If unsure, ask your IT team or search "tar CVE-2026-59871" on the vendor's site.
CVE-2026-59871 (tar) — CWE-704 / CVSS v3 5.3
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: `pax.ts` / `parseKV` / `path` / `linkpath`
Patched: `7.5.18` — 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
**A vulnerability** (CWE-704) exists in tar. Attackers reach the vulnerable code path via ``pax.ts`` without authentication.
📍 Affected scope
tar — . Attack surface: `pax.ts` / `parseKV` / `path` / `linkpath`.
🔥 Severity
Severity: Medium (CVSS 5.3/10). Risk of unauthorized operations or information disclosure
🔧 How to fix
Update to **7.5.18**.
🛡️ 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 'tar' .` 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
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1Identify exposure identify
grep -r 'tar' . | 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 `tar` を grep し、稼働しているサービス・バージョンを把握する。
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6Apply patch patch
Upgrade tar to 7.5.18ステージング環境で 7.5.18 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。
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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
npm
tar
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.5.18"}]}]
References
- web https://github.com/isaacs/node-tar/commit/e02a4e9e013c4be95302e2eb2047a942b883c27b
- web https://github.com/isaacs/node-tar/releases/tag/v7.5.18
- web https://github.com/isaacs/node-tar/security/advisories/GHSA-w8wr-v893-vjvp
- web https://nvd.nist.gov/vuln/detail/CVE-2026-59871
- web https://github.com/advisories/GHSA-w8wr-v893-vjvp