{"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":"2026-08-21T12:13:53.723Z"},"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 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 10","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","packageName":"tar","defaultStatus":"affected","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 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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":"2026-08-21T12:13:53.723Z"},"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"}}]}}