Vulnerability in GNU Tar
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.
EPSS: 0.001 (3.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N.
Affected products
- Gnu Tar — versions 1.35
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat Hardened Images — versions 1.35-9.2.hum1
- Red Hat Openshift Container Platform 4
- Redhat Enterprise_linux — versions 10.0, 8.0, 9.0
- Redhat Openshift_container_platform — versions 4.0
Weakness classification (CWE)
References
- secalert@redhat.com (x_refsource_REDHAT, vdb-entry, Vendor Advisory)
- secalert@redhat.com (x_refsource_REDHAT, issue-tracking, Issue Tracking, Vendor Advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory, Vendor Advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
- secalert@redhat.com (x_refsource_REDHAT, vendor-advisory)
Frequently asked questions
- What is CVE-2026-18508?
- CVE-2026-18508 is a medium-severity vulnerability in GNU Tar, classified under Improper Link Resolution Before File Access. CVSS score: 4.4/10. Published 2026-08-03.
- How severe is CVE-2026-18508?
- Medium severity. CVSS v3 base score is 4.4 out of 10.