CVE-2026-66484 is a vulnerability in GNU Cpio
Published on August 10, 2026
Path Traversal in GNU cpio
GNU cpio contains a Path Traversal vulnerability in its tar archive extraction functionality. When extracting a tar archive in copy-in mode with the --no-absolute-filenames option, the extracted file name is normalized but the tar hard-link target is passed to the link_to_name function without equivalent sanitization before calling link function. A tar archive provided by an attacker, containing a hard-link entry whose linkname is set to an absolute path outside the extraction directory, can cause cpio to create a hard link to an existing file outside the intended extraction directory, breaking the expected guarantee of --no-absolute-filenames and allowing archive-controlled linkage to external files.
This issue has been fixed in commit e2b9cbdd3354d2b1569b7390d1bc15c1930559ad
Vulnerability Analysis
CVE-2026-66484 is exploitable with local system access. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
What is a Directory traversal Vulnerability?
The software uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the software does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
CVE-2026-66484 has been classified to as a Directory traversal vulnerability or weakness.
Products Associated with CVE-2026-66484
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Affected Versions
GNU cpio:- Before and including 2.15 is affected.