CVE-2026-39243
mediumpriority · track · 0EPSS 0.003 · 23 %ileEUUSEPSS · scored 2026-10-28
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-jwp9-9v96-94mxdecompress allows arbitrary hardlink creation during archive extraction2026-07-10ghsa · osvUS
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.
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (9)
External citations — patches, advisories, analysis.
- https://github.com/kevva/decompresscnnvd
- https://github.com/kevva/decompress/issues/113cnnvd
- https://www.npmjs.com/package/decompresscnnvd
- https://github.com/kevva/decompressenisa_euvd
- https://github.com/kevva/decompress/issues/113enisa_euvd
- https://www.npmjs.com/package/decompressenisa_euvd
- https://github.com/kevva/decompressProductnvd
- https://github.com/kevva/decompress/issues/113ExploitVendor Advisorynvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan