{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-18508", "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "state": "PUBLISHED", "assignerShortName": "redhat", "dateReserved": "2026-07-31T17:08:04.550Z", "datePublished": "2026-08-03T14:51:41.340Z", "dateUpdated": "2026-09-01T14:15:40.173Z" }, "containers": { "cna": { "title": "Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite", "metrics": [ { "other": { "content": { "value": "Moderate", "namespace": "https://access.redhat.com/security/updates/classification/" }, "type": "Red Hat severity rating" } }, { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "version": "3.1" }, "format": "CVSS" } ], "descriptions": [ { "lang": "en", "value": "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." } ], "affected": [ { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 10", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "affected", "versions": [ { "version": "2:1.35-13.el10_2", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/o:redhat:enterprise_linux:10.2" ] }, { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 9", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "affected", "versions": [ { "version": "2:1.34-13.el9_8", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/o:redhat:enterprise_linux:9::baseos" ] }, { "vendor": "Red Hat", "product": "Red Hat Discovery 2", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "discovery/discovery-server-rhel9", "defaultStatus": "affected", "versions": [ { "version": "1788205779", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:discovery:2::el9" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://catalog.redhat.com/software/containers/", "packageName": "tar-main", "defaultStatus": "affected", "versions": [ { "version": "1.35-9.2.hum1", "lessThan": "*", "versionType": "rpm", "status": "unaffected" } ], "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 6", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "unknown", "cpes": [ "cpe:/o:redhat:enterprise_linux:6" ] }, { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 7", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "unknown", "cpes": [ "cpe:/o:redhat:enterprise_linux:7" ] }, { "vendor": "Red Hat", "product": "Red Hat Enterprise Linux 8", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "tar", "defaultStatus": "affected", "cpes": [ "cpe:/o:redhat:enterprise_linux:8" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "aardvark-dns", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "chunkah", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "grafana12.4", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "grafana13.1", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "netavark", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "nodejs26", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "python-cryptography", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rust", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "rust-rpm-sequoia", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat Hardened Images", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "yarnpkg", "defaultStatus": "unaffected", "cpes": [ "cpe:/a:redhat:hummingbird:1" ] }, { "vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "openshift/ose-rhel-coreos-8", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:openshift:4" ] }, { "vendor": "Red Hat", "product": "Red Hat OpenShift Container Platform 4", "collectionURL": "https://access.redhat.com/downloads/content/package-browser/", "packageName": "openshift/ose-rhel-coreos-9", "defaultStatus": "affected", "cpes": [ "cpe:/a:redhat:openshift:4" ] } ], "references": [ { "url": "https://access.redhat.com/errata/RHSA-2026:50807", "name": "RHSA-2026:50807", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/errata/RHSA-2026:61581", "name": "RHSA-2026:61581", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/errata/RHSA-2026:61586", "name": "RHSA-2026:61586", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/errata/RHSA-2026:61783", "name": "RHSA-2026:61783", "tags": [ "vendor-advisory", "x_refsource_REDHAT" ] }, { "url": "https://access.redhat.com/security/cve/CVE-2026-18508", "tags": [ "vdb-entry", "x_refsource_REDHAT" ] }, { "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2509843", "name": "RHBZ#2509843", "tags": [ "issue-tracking", "x_refsource_REDHAT" ] } ], "datePublic": "2026-07-31T00:00:00.000Z", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-59", "description": "Improper Link Resolution Before File Access ('Link Following')", "lang": "en", "type": "CWE" } ] } ], "x_redhatCweChain": "CWE-59: Improper Link Resolution Before File Access ('Link Following')", "workarounds": [ { "lang": "en", "value": "Do not use --one-top-level as the sole confinement mechanism when extracting untrusted archives. Prefer extracting as an unprivileged user into a freshly created empty directory after changing into that directory (mkdir and cd), avoid extracting as root from sensitive working directories such as /, and follow the GNU tar security guidance for untrusted archives." } ], "timeline": [ { "lang": "en", "time": "2026-07-31T16:57:51.102Z", "value": "Reported to Red Hat." }, { "lang": "en", "time": "2026-07-31T00:00:00.000Z", "value": "Made public." } ], "credits": [ { "lang": "en", "value": "This issue was discovered by Pavel Cahyna (Red Hat)." } ], "providerMetadata": { "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749", "shortName": "redhat", "dateUpdated": "2026-09-01T14:15:40.173Z" }, "x_generator": { "engine": "cvelib 1.8.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-08-03T16:02:27.313193Z", "id": "CVE-2026-18508", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-08-03T16:06:11.931Z" } } ] } }