Vulnerability in tar (CVE-2026-53655)
Summary
Vulnerability in tar (CVE-2026-53655). Data can be tampered with by attackers. Exploitable via tar. Mitigation: upgrade to 7.5.16 or later.
Original description
The description as published by the source.
node-tar is a full-featured Tar for Node.js. Prior to 7.5.16, tar (node-tar) applies a PAX extended header's size= record (and other PAX overrides) to the next header entry of any type, including intermediary metadata headers such as a GNU long-name (L) or long-link (K) entry. Per POSIX pax, a PAX extended header (x) describes the next file entry, not the intermediary extension headers that may sit between the x header and the file it annotates. Because node-tar lets the PAX size override the byte length of an intervening L/K/x header, an attacker can desynchronize node-tar's stream cursor relative to every other mainstream tar implementation (GNU tar, libarchive/bsdtar, Python tarfile, and the now-fixed tar-rs / astral-tokio-tar). The result is a tar parser interpretation differential (CWE-436): a single crafted archive yields a different set of members under node-tar than under the reference tar tools. An attacker can use this to hide a member from one parser while it is visible to another, which defeats security tooling whose scanner and extractor disagree on archive contents (e.g. a malware/secret scanner that lists entries with one library while a downstream step extracts with another) This vulnerability is fixed in 7.5.16.
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-2026-53655 has been found in tar.
Attackers can target a specific entry point like tar over the network to misuse the product.
Data can be tampered with by attackers. CVSS score: 5.5/10.
What to do: upgrade tar to 7.5.16 or later.
If unsure, ask your IT team or search "tar CVE-2026-53655" on the vendor's site.
CVE-2026-53655 (tar) — CWE-436 / CVSS v3 5.5
Attack vector: local / unauthenticated
Attack surface: tar / size / tarfile / npm
Patched: 7.5.16 — 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-436) exists in tar. Attackers reach the vulnerable code path via tar without authentication.
Check the vendor advisory for the affected versions of tar. Attack surface: tar / size / tarfile / npm.
Severity: Medium (CVSS 5.5/10). Data can be tampered with by attackers.
Update to 7.5.16.
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
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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。 -
2Apply patch patch
Upgrade tar to 7.5.16ステージング環境で 7.5.16 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-2026-53655 node-tar
- Ubuntu UBUNTU-CVE-2026-53655 node-tar
References
- advisory github.com
- advisory github.com
- advisory nvd.nist.gov
- package github.com
- web github.com