Read the docs
TI-2026-28283 Aliases CVE-2026-39243GHSA-jwp9-9v96-94mx

decompress before 4.2.2 allows arbitrary hardlink creation during archive extraction…

Priority MEDIUM 58CWE-59Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 1 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-59 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00301 23rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial Red Hat: 1 advisoryRed Hat: 1 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
—decompress (npm)up to 4.2.1—No fix listedGHSA-jwp9-9v96-94mx
  • — Vendor— Affected all versions Fixed in — No fix listed CNA
  • decompress (npm) Vendor— Affected up to 4.2.1 Fixed in — No fix listed GHSA-jwp9-9v96-94mx

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:decompress_project:decompress:*:*:*:*:*:node.js:*:*up to 4.2.1VulnerableDecompress Project
  • cpe:2.3:a:decompress_project:decompress:*:*:*:*:*:node.js:*:* Versions up to 4.2.1 Vulnerable ·Decompress Project

Remediation

Red Hat 1 advisory

  • RHSA-2026:37577 Released 2026-07-10 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images aspnetcore-runtime-8.0-8.0.28-1.1.hum1@aarch64, aspnetcore-runtime-8.0-8.0.28-1.1.hum1@x86_64, aspnetcore-runtime-dbg-8.0-8.0.28-1.1.hum1@aarch64 +22

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Advanced Cluster Management for Kubernetes 2AffectedNo fix yet: Fix deferred
Red Hat Build of KeycloakAffectedNo fix yet: Fix deferred
Red Hat Hardened ImagesFixed RHSA-2026:37577

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-39243
  2. 2026-10-03 Alias added: GHSA-jwp9-9v96-94mx

References

Exploit 1

Advisory 1

Other 2

  • TI-2026-28286 decompress before 4.2.2 allows arbitrary symlink creation during archive extraction. CVSS 3.1HIGH 7.5
  • TI-2026-28285 decompress before 4.2.2 contains an improper path containment check that enables… CVSS 3.1MEDIUM 6.2
  • TI-2020-09798 The decompress package before 4.2.1 for Node.js is vulnerable to Arbitrary File Write via… CVSS 3.1CRITICAL 9.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences