CVE-2026-18508
mediumA flaw was found in GNU tar.
Vendor / product: Gnu — tar
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
4.4
4.4 (CVSS v3.1)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N Severity source: NVD CVSS v3.1 (secalert@redhat.com)
Timeline (UTC)
Published: 2026-08-03 16:16
Modified: 2026-10-30 13:18
NVD status: Modified
Last synced 1 day ago
Verified against the source API 2026-10-30 13:38 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
gnu / tar 1.35
redhat / openshift_container_platform 4.0
redhat / enterprise_linux 8.0, 9.0, 10.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Vendor advisory: https://access.redhat.com/errata/RHSA-2026:50807
Vendor advisory: https://access.redhat.com/security/cve/CVE-2026-18508
Vendor advisory: https://bugzilla.redhat.com/show_bug.cgi?id=2509843
References
- https://access.redhat.com/errata/RHSA-2026:50807 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:61581 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:61586 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:61783 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:66018 secalert@redhat.com
- https://access.redhat.com/errata/RHSA-2026:70390 secalert@redhat.com
- https://access.redhat.com/security/cve/CVE-2026-18508 secalert@redhat.com
- https://bugzilla.redhat.com/show_bug.cgi?id=2509843 secalert@redhat.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-30 13:38 UTC · record ↗