CVE-2026-18508
Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite
At a glance
- Severity
- MEDIUM 4.4
- EPSS
- EPSS 0.14 % · percentile 3 (2026-10-28)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- redhat
- NVD status
- Modified
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.
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 4.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N | redhat |
| CVSS 3.1 | MEDIUM 4.4 | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N | NVD · secalert@redhat.com (Secondary) |
Weaknesses (CWE)
European references
- ENISA EUVD · EUVD-2026-52327
- GCVE · GCVE-0-2026-18508
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1249 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:gnu:tar:1.35:*:*:*:*:*:*:*cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Red Hat · Red Hat Enterprise Linux 10 | unaffected 2:1.35-13.el10_2 < * |
| Red Hat · Red Hat Enterprise Linux 8 | unaffected 2:1.30-13.el8_10 < * |
| Red Hat · Red Hat Enterprise Linux 9 | unaffected 2:1.34-13.el9_8 < * |
| Red Hat · Red Hat Discovery 2 | unaffected 1788205779 < * |
| Red Hat · Red Hat Hardened Images | unaffected 1.35-9.2.hum1 < * |
| Red Hat · Red Hat Update Infrastructure 5 | unaffected 1788880445 < * |
| Red Hat · Red Hat Update Infrastructure 5 | unaffected 1788880464 < * |
| Red Hat · Red Hat Update Infrastructure 5 | unaffected 1788880456 < * |
| Red Hat · Red Hat Update Infrastructure 5 | unaffected 1788765051 < * |
| Red Hat · Red Hat Update Infrastructure 5 | unaffected 1788880581 < * |
| Red Hat · Red Hat Enterprise Linux 6 | |
| Red Hat · Red Hat Enterprise Linux 7 | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images | |
| Red Hat · Red Hat Hardened Images |
References
- https://access.redhat.com/errata/RHSA-2026:50807
- https://access.redhat.com/errata/RHSA-2026:61581
- https://access.redhat.com/errata/RHSA-2026:61586
- https://access.redhat.com/errata/RHSA-2026:61783
- https://access.redhat.com/errata/RHSA-2026:66018
- https://access.redhat.com/errata/RHSA-2026:70390
- https://access.redhat.com/security/cve/CVE-2026-18508
- https://bugzilla.redhat.com/show_bug.cgi?id=2509843
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |