CVE-2026-39243 (GCVE-0-2026-39243)

Vulnerability from cvelistv5 – Published: 2026-07-09 00:00 – Updated: 2026-07-10 15:25
VLAI
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.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
SSVC
Exploitation: poc Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • n/a
  • CWE-59 - Improper Link Resolution Before File Access ('Link Following')
Assigner
References
Show details on NVD website
To clipboard 

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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