Quick answers
- Is CVE-2026-66484 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-66484 being exploited in the wild.
- How severe is CVE-2026-66484?
- Informational severity, with a CVSS score of 4.2, published 10 August 2026.
- Which products and versions are affected?
- Gnu Cpio through 2.15.
- Is there a fix for CVE-2026-66484?
- A patch was published on 2026-08-28: Fix committed (tar: keep symbolic link targets intact under --no-absolute-filenames) Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-66484 attacked?
- It is attacked with local access.
- Am I affected by CVE-2026-66484?
- Check whether you run Gnu Cpio at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
This is a path traversal vulnerability (CWE-22) in GNU cpio's tar archive extraction functionality. When extracting with the --no-absolute-filenames option enabled, the extracted file name is properly normalized, but the hard-link target (linkname field in tar entries) bypasses this sanitization before being passed to the link function. An attacker can craft a tar archive containing a hard-link entry with an absolute path outside the extraction directory to cause cpio to create hard links to external files, circumventing the safety guarantee. The vulnerability affects cpio versions through 2.15 and has been fixed in subsequent commits including e2b9cbdd3354d2b1569b7390d1bc15c1930559ad.
Affected products
- GNU cpio through 2.15
Timeline
- 2026-08-10: disclosed
- 2026-08-28: patched: Fix committed (tar: keep symbolic link targets intact under --no-absolute-filenames)