Vulnerability in tar (CVE-2026-59874)
Summary
Vulnerability in tar (CVE-2026-59874). Risk of unauthorized operations or information disclosure. Exploitable via poc.mjs. Mitigation: upgrade to 7.5.18 or later.
Original description
The description as published by the source.
node-tar is a tar archive manipulation library for Node.js. Prior to 7.5.18, tar.replace accepts a checksum-valid tar header with a negative base-256 encoded entry size, causing the archive scanner to make no progress while repeatedly parsing the same header. This issue is fixed in version 7.5.18.
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-2026-59874 has been found in tar.
Attackers can target a specific entry point like poc.mjs over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 7.5/10.
What to do: upgrade tar to 7.5.18 or later.
If unsure, ask your IT team or search "tar CVE-2026-59874" on the vendor's site.
CVE-2026-59874 (tar) — CWE-835 / CVSS v3 7.5
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: poc.mjs
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.
A vulnerability (CWE-835) exists in tar. Attackers reach the vulnerable code path via poc.mjs without authentication.
Check the vendor advisory for the affected versions of tar. Attack surface: poc.mjs.
Severity: High (CVSS 7.5/10). Risk of unauthorized operations or information disclosure.
Update to 7.5.18.
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 'tar' . 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 '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。 -
2Apply 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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-59874 node-tar
- Ubuntu UBUNTU-CVE-2026-59874 node-tar
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- patch github.com
- web github.com
- web github.com