CVE-2026-18508 — MEDIUM (4.4)

Vulnerability Description

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.

CVSS Score

4.4

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

LOW

Integrity

LOW

Availability

NONE

Related Weaknesses (CWE)

CWE-59

References

FAQ

What is CVE-2026-18508?

CVE-2026-18508 is a vulnerability with a CVSS score of 4.4 (MEDIUM). 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 extract...

How severe is CVE-2026-18508?

CVE-2026-18508 has been rated MEDIUM with a CVSS base score of 4.4/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-18508?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.