Medium

decompress allows arbitrary hardlink creation during archive extraction

  • Disclosed: 10.07.2026
  • Updated: 11.10.2026 10:22

decompress before 4.2.2 allows arbitrary hardlink creation during archive extraction, enabling file read disclosure and file corruption. When processing hardlink entries (type === 'link'), the x.linkname field from the archive is passed directly to fs.link() without validation (index.js line 113). An attacker can craft an archive with a hardlink entry whose linkname is an absolute path to any file on the same filesystem. This creates a hardlink inside the extraction directory that shares the same inode as the target file, enabling both reading and overwriting the original file's content. Hardlinks are limited to files on the same filesystem and cannot target directories.

Affected software

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PlatformPackageVulnerable versionsFixed in
npm package decompress <= 4.2.1 no fix

References

CVSS score 5.5/10
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Weakness (CWE)
CWE-59
Platform
npm
Package
decompress
Disclosed
10.07.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-jwp9-9v96-94mx - CC BY 4.0

Vulnerability history: decompress

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
5
First → latest
09.2020 09.2026
Without a fix
4
Exploited in attacks
0

Severity breakdown

  • Critical 3
  • Medium 2

Disclosures per year

  1. 2020: 1
  2. 2021: 0
  3. 2022: 0
  4. 2023: 0
  5. 2024: 0
  6. 2025: 0
  7. 2026: 4
  1. Critical · 9.1 CVE-2026-101894 <= 4.2.1 no fix
  2. decompress allows arbitrary hardlink creation during archive extraction this entry
    Medium · 5.5 CVE-2026-39243 <= 4.2.1 no fix
  3. Medium · 6.4 CVE-2026-10732 <= 4.2.1 no fix
  4. Critical · 9.8 CVE-2020-12265 < 4.2.1 4.2.1

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