{"id":"CVE-2026-85731","state":"PUBLISHED","title":"oras-go: Arbitrary file write outside file.Store root via symlink-chain bypass in tar extraction (pushDir)","description":"oras-go is a Go library for managing OCI artifacts. Prior to 2.6.2, content/file.Store extraction of OCI layers marked with io.deis.oras.content.unpack=true can write outside the store working directory. The pushDir path through extractTarDirectory and ensureLinkPath validates symlink targets lexically, resolveRelToBase skips its parent-symlink walk for root-level entries, and writeFile follows a terminal symlink when opening a regular file. A malicious archive can therefore create a symlink chain whose lexical target remains inside the extraction root but whose resolved target is an attacker-selected absolute path, then overwrite that target with a same-named regular-file entry even when AllowPathTraversalOnWrite is false. Pulling an attacker-controlled artifact can create or overwrite any file writable by the process and may lead to code execution. This issue is fixed in version 2.6.2.","publishedAt":"2026-09-16T16:24:48.905Z","updatedAt":"2026-09-16T17:25:07.159Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["oras-project oras-go"],"affected":[{"vendor":"oras-project","product":"oras-go","versions":[{"version":"< 2.6.2","status":"affected"}]}],"references":["https://github.com/oras-project/oras-go/security/advisories/GHSA-m37j-52j7-pjw7","https://github.com/oras-project/oras-go/commit/adab2f25ea95ef4e6e41f50db9266a6701399422","https://github.com/oras-project/oras-go/releases/tag/v2.6.2"],"weaknesses":["CWE-22","CWE-59"],"ingestedAt":"2026-10-29T20:13:15.269Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/85xxx/CVE-2026-85731.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-85731","state":"PUBLISHED","datePublished":"2026-09-16T16:24:48.905Z","dateUpdated":"2026-09-16T17:25:07.159Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-09-04T14:45:10.649Z"},"containers":{"cna":{"title":"oras-go: Arbitrary file write outside file.Store root via symlink-chain bypass in tar extraction (pushDir)","descriptions":[{"lang":"en","value":"oras-go is a Go library for managing OCI artifacts. Prior to 2.6.2, content/file.Store extraction of OCI layers marked with io.deis.oras.content.unpack=true can write outside the store working directory. The pushDir path through extractTarDirectory and ensureLinkPath validates symlink targets lexically, resolveRelToBase skips its parent-symlink walk for root-level entries, and writeFile follows a terminal symlink when opening a regular file. A malicious archive can therefore create a symlink chain whose lexical target remains inside the extraction root but whose resolved target is an attacker-selected absolute path, then overwrite that target with a same-named regular-file entry even when AllowPathTraversalOnWrite is false. Pulling an attacker-controlled artifact can create or overwrite any file writable by the process and may lead to code execution. This issue is fixed in version 2.6.2."}],"affected":[{"vendor":"oras-project","product":"oras-go","versions":[{"version":"< 2.6.2","status":"affected"}]}],"references":[{"url":"https://github.com/oras-project/oras-go/security/advisories/GHSA-m37j-52j7-pjw7","name":"https://github.com/oras-project/oras-go/security/advisories/GHSA-m37j-52j7-pjw7","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/oras-project/oras-go/commit/adab2f25ea95ef4e6e41f50db9266a6701399422","name":"https://github.com/oras-project/oras-go/commit/adab2f25ea95ef4e6e41f50db9266a6701399422","tags":["x_refsource_MISC"]},{"url":"https://github.com/oras-project/oras-go/releases/tag/v2.6.2","name":"https://github.com/oras-project/oras-go/releases/tag/v2.6.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.8,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","lang":"en","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-59","lang":"en","description":"CWE-59: Improper Link Resolution Before File Access ('Link Following')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-16T16:24:48.905Z"},"source":{"advisory":"GHSA-m37j-52j7-pjw7","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/oras-project/oras-go/security/advisories/GHSA-m37j-52j7-pjw7","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-16T17:24:00.719255Z","id":"CVE-2026-85731","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-16T17:25:07.159Z"}}]}}}