CVE-2026-18508
A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.
- Published Aug 3, 2026
- CVSS 4.4 medium
- 0.1% chance of exploitation in the next 30 days (EPSS)
- A fix is available