node-tar Vulnerable to Arbitrary File Creation/Overwrite via Hardlink Path Traversal

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.2 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N

EPSS

• CVE-2026-24842: 0.61% estimated exploitation activity in the next 30 days; percentile 49.14 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary node-tar contains a vulnerability where the security check for hardlink entries uses different path resolution semantics than the actual hardlink creation logic. This mismatch allows an attacker to craft a malicious TAR archive that bypasses path traversal protections and creates hardlinks to arbitrary files outside the extraction directory. Details The vulnerability exists in lib/unpack.js. When extracting a hardlink, two functions handle the linkpath differently: Security check in [STRIPABSOLUTEPATH]: Hardlink creation in [HARDLINK]: Example: An application extracts a TAR using tar.extract({ cwd: '/var/app/uploads/' }). The TAR contains entry a/b/c/d/x as a hardlink to ../../../../etc/passwd. - Security check resolves the linkpath relative to the entry's parent directory: a/b/c/d/ + ../../../../etc/passwd = etc/passwd. No ../ prefix, so it passes. - Hardlink creation resolves the linkpath relative to the extraction directory (this.cwd): /var/app/uploads/ +…

Published by the source

28 Jan 2026, 16:35 UTC

Last modified by the source

10 Sep 2026, 03:50 UTC

Source last checked

26 Oct 2026, 12:41 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-34x7-hfp2-rc4v

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-34x7-hfp2-rc4v

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# Patch Next advisory brief: CVE-2026-24842

Advisory: node-tar Vulnerable to Arbitrary File Creation/Overwrite via Hardlink Path Traversal
IDs: CVE-2026-24842, GHSA-34x7-hfp2-rc4v
Record: https://patchnext.com/advisories/cve-2026-24842 (revision 2, source checked 26 Oct 2026, 12:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tar 7.5.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm tar: affected < 7.5.7; fixed in 7.5.7

## Suggested inspection (read-only)
- `npm ls tar --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on tar.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-34x7-hfp2-rc4v (OSV record GHSA-34x7-hfp2-rc4v lists affected ranges: npm tar >=0 <7.5.7 (fixed))
- Verified: https://github.com/advisories/GHSA-34x7-hfp2-rc4v (GitHub-reviewed advisory GHSA-34x7-hfp2-rc4v lists affected ranges: npm tar >=0 <7.5.7)

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