{"id":"CVE-2026-18508","title":"A flaw was found in GNU tar","summary":"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 arch…","severity":"medium","cvss":4.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","cwe":["CWE-59"],"vendor":"gnu","product":"tar","affected":["tar = 1.35","openshift_container_platform = 4.0","enterprise_linux = 8.0","enterprise_linux = 9.0","enterprise_linux = 10.0"],"published":"2026-08-03","updated":"2026-09-22","sourceUpdated":"2026-09-22T22:17:11.493","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-18508","references":[{"url":"https://access.redhat.com/errata/RHSA-2026:50807","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:61581","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:61586","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:61783","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:66018","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2026:70390","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2026-18508","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2509843","label":"secalert@redhat.com"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-18508.json"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-18508"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18508"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"epss":0.00141,"epssPercentile":0.03802,"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-08-03T16:02:27.313193Z"},"ingestedAt":"2026-09-14T05:37:36.692Z","patched":["enterprise_linux_baseos_v_10","enterprise_linux_baseos_v_8","enterprise_linux_baseos_v_9","discovery 2","hardened_images","update_infrastructure 5"],"slug":"CVE-2026-18508","body":"## Overview\n\nA 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.\n\n## Affected\n\n- `tar = 1.35`\n- `openshift_container_platform = 4.0`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n- `enterprise_linux = 10.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:61586** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 10) · released 2026-09-01 · [advisory](https://access.redhat.com/errata/RHSA-2026:61586)\n- **RHSA-2026:70390** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8) · released 2026-09-22 · [advisory](https://access.redhat.com/errata/RHSA-2026:70390)\n- **RHSA-2026:61581** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 9) · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61581)\n- **RHSA-2026:61783** · Red Hat · fixed in: Red Hat Discovery 2 · released 2026-08-31 · [advisory](https://access.redhat.com/errata/RHSA-2026:61783)\n- **RHSA-2026:50807** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-08-05 · [advisory](https://access.redhat.com/errata/RHSA-2026:50807)\n- **RHSA-2026:66018** · Red Hat · fixed in: Red Hat Update Infrastructure 5 · released 2026-09-09 · [advisory](https://access.redhat.com/errata/RHSA-2026:66018)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat OpenShift Container Platform 4 · updated 2026-09-22 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-18508.json)","depth":"sunlit","depthScore":24,"depthScoreParts":{"impact":24.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}