🛡️ CVE-2026-18508 on Ubuntu — tar

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Distribution advisory

This page covers CVE-2026-18508 as tracked by Ubuntu, for the package tar. No fixed version has been recorded for this distribution yet.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity low, availability none.

Affected software

UBUNTU-CVE-2026-18508 is recorded against 1 package.

  • tar

Timeline and source

Published on 3 August 2026 and last revised on 6 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
bugzilla.redhat.com (Report)
access.redhat.com (Report)

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2026-08-03
Updated 2026-08-11
Modified 2026-08-06
Fix URL N/A

Affected Packages

Software From version Fixed in
tar — —

Similar Threats

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