{"api_version":"1","generated_at":"2026-08-22T17:47:31+00:00","cve":"CVE-2026-18508","urls":{"html":"https://cve.report/CVE-2026-18508","api":"https://cve.report/api/cve/CVE-2026-18508.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-18508","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-18508"},"summary":{"title":"Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite","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.","state":"PUBLISHED","assigner":"redhat","published_at":"2026-08-03 16:16:28","updated_at":"2026-08-21 13:16:55"},"problem_types":["CWE-59","CWE-59 Improper Link Resolution Before File Access ('Link Following')"],"metrics":[{"version":"3.1","source":"secalert@redhat.com","type":"Secondary","score":"4.4","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","baseScore":4.4,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"CVSS","score":"4.4","severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","data":{"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"}}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-18508","name":"https://access.redhat.com/security/cve/CVE-2026-18508","refsource":"secalert@redhat.com","tags":["Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://access.redhat.com/errata/RHSA-2026:50807","name":"https://access.redhat.com/errata/RHSA-2026:50807","refsource":"secalert@redhat.com","tags":["Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2509843","name":"https://bugzilla.redhat.com/show_bug.cgi?id=2509843","refsource":"secalert@redhat.com","tags":["Issue Tracking","Vendor Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-18508","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-18508","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"unaffected 1.35-9.2.hum1 * rpm","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat Hardened Images","version":"","platforms":[]},{"source":"CNA","vendor":"Red Hat","product":"Red Hat OpenShift Container Platform 4","version":"","platforms":[]}],"timeline":[{"source":"CNA","time":"2026-07-31T16:57:51.102Z","lang":"en","value":"Reported to Red Hat."},{"source":"CNA","time":"2026-07-31T00:00:00.000Z","lang":"en","value":"Made public."}],"solutions":[],"workarounds":[{"source":"CNA","title":"","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.","time":"","lang":"en"}],"exploits":[],"credits":[{"source":"CNA","value":"This issue was discovered by Pavel Cahyna (Red Hat).","lang":"en"}],"nvd_cpes":[{"cve_year":"2026","cve_id":"18508","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"gnu","cpe5":"tar","cpe6":"1.35","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2026","cve_id":"18508","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"redhat","cpe5":"enterprise_linux","cpe6":"10.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2026","cve_id":"18508","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"redhat","cpe5":"enterprise_linux","cpe6":"8.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2026","cve_id":"18508","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"redhat","cpe5":"enterprise_linux","cpe6":"9.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2026","cve_id":"18508","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"redhat","cpe5":"openshift_container_platform","cpe6":"4.0","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"18508","cve":"CVE-2026-18508","epss":"0.001360000","percentile":"0.034810000","score_date":"2026-08-21","updated_at":"2026-08-22 00:12:48"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-18508","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-08-03T16:02:27.313193Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-08-03T16:06:11.931Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"collectionURL":"https://catalog.redhat.com/software/containers/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"affected","packageName":"tar-main","product":"Red Hat Hardened Images","vendor":"Red Hat","versions":[{"lessThan":"*","status":"unaffected","version":"1.35-9.2.hum1","versionType":"rpm"}]},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"],"defaultStatus":"affected","packageName":"tar","product":"Red Hat Enterprise Linux 10","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"],"defaultStatus":"unknown","packageName":"tar","product":"Red Hat Enterprise Linux 6","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"],"defaultStatus":"unknown","packageName":"tar","product":"Red Hat Enterprise Linux 7","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"],"defaultStatus":"affected","packageName":"tar","product":"Red Hat Enterprise Linux 8","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"],"defaultStatus":"affected","packageName":"tar","product":"Red Hat Enterprise Linux 9","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"aardvark-dns","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"chunkah","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"grafana12.4","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"grafana13.1","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"netavark","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"nodejs26","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"python-cryptography","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"rust","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"rust-rpm-sequoia","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:hummingbird:1"],"defaultStatus":"unaffected","packageName":"yarnpkg","product":"Red Hat Hardened Images","vendor":"Red Hat"},{"collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/a:redhat:openshift:4"],"defaultStatus":"affected","packageName":"openshift/ose-rhel-coreos-9","product":"Red Hat OpenShift Container Platform 4","vendor":"Red Hat"}],"credits":[{"lang":"en","value":"This issue was discovered by Pavel Cahyna (Red Hat)."}],"datePublic":"2026-07-31T00:00:00.000Z","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."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Moderate"},"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"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-59","description":"Improper Link Resolution Before File Access ('Link Following')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-08-21T12:13:53.723Z","orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","shortName":"redhat"},"references":[{"name":"RHSA-2026:50807","tags":["vendor-advisory","x_refsource_REDHAT"],"url":"https://access.redhat.com/errata/RHSA-2026:50807"},{"tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-18508"},{"name":"RHBZ#2509843","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2509843"}],"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."}],"title":"Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite","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."}],"x_generator":{"engine":"cvelib 1.8.0"},"x_redhatCweChain":"CWE-59: Improper Link Resolution Before File Access ('Link Following')"}},"cveMetadata":{"assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","assignerShortName":"redhat","cveId":"CVE-2026-18508","datePublished":"2026-08-03T14:51:41.340Z","dateReserved":"2026-07-31T17:08:04.550Z","dateUpdated":"2026-08-21T12:13:53.723Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-03 16:16:28","lastModifiedDate":"2026-08-21 13:16:55","problem_types":["CWE-59","CWE-59 Improper Link Resolution Before File Access ('Link Following')"],"metrics":{"cvssMetricV31":[{"source":"secalert@redhat.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N","baseScore":4.4,"baseSeverity":"MEDIUM","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":1.8,"impactScore":2.5}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-08-03T16:02:27.313193Z","id":"CVE-2026-18508","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:gnu:tar:1.35:*:*:*:*:*:*:*","matchCriteriaId":"753D60F2-E001-49F6-A9B7-D8FCDE7E26BD"},{"vulnerable":true,"criteria":"cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*","matchCriteriaId":"932D137F-528B-4526-9A89-CD59FA1AB0FE"},{"vulnerable":true,"criteria":"cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*","matchCriteriaId":"F4CFF558-3C47-480D-A2F0-BABF26042943"},{"vulnerable":true,"criteria":"cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*","matchCriteriaId":"7F6FB57C-2BC7-487C-96DD-132683AEB35D"},{"vulnerable":true,"criteria":"cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*","matchCriteriaId":"D65C2163-CFC2-4ABB-8F4E-CB09CEBD006C"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"18508","Ordinal":"1","Title":"Tar: tar: --one-top-level hardlink targets not confined to top-l","CVE":"CVE-2026-18508","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"18508","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Tar: tar: --one-top-level hardlink targets not confined to top-l"}]}}}