CVE-2026-39243

Aliases:GHSA-jwp9-9v96-94mx

Advisory lineage Upstream: 0 Downstream: 1

Downstream

RHSA-2026:37577

Analyzed

Published: 09 Jul 2026, 00:00

Last modified:10 Jul 2026, 15:25

Vulnerability Summary

Overall Risk (default)

medium

32/100

CVSS Score

5.5 MEDIUM

v3.1 (cve.org)

EPSS Score

0.3% LOW

0% probability 0.00%

KEV

Not listed

Ransomware

No reports

Public exploits

1 found

Dark Web

Not detected

Timeline

09 Jul 2026, 00:00

Published

Vulnerability first disclosed

10 Jul 2026, 15:25

Last Modified

Vulnerability information updated

Description

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.

CVSS Metrics

v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

EPSS Trends

Current EPSS score: 0.30%• Percentile: 23%

Techniques & Countermeasures

CWE-59•Improper Link Resolution Before File Access ('Link Following')
The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Systems

decompress_project•decompress
≤ 4.2.1
Npm•decompress
≤ 4.2.1