{"id":"CVE-2026-63343","state":"PUBLISHED","title":"Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root","description":"Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a `metadata.yaml` symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The `exec-output` and `templates/` paths were patched in a prior release using `Lstat` rejection and `os.OpenRoot` confinement; `metadata.yaml` was not included in either patch and remains exploitable. Version 7.3.0 patches the issue.","publishedAt":"2026-08-21T14:53:26.109Z","updatedAt":"2026-08-21T21:44:03.623Z","severity":{"score":9.9,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["lxc incus"],"affected":[{"vendor":"lxc","product":"incus","versions":[{"version":"< 7.3.0","status":"affected"}]}],"references":["https://github.com/lxc/incus/security/advisories/GHSA-fmjx-5j3g-997p"],"weaknesses":["CWE-73"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/63xxx/CVE-2026-63343.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-63343","state":"PUBLISHED","datePublished":"2026-08-21T14:53:26.109Z","dateUpdated":"2026-08-21T21:44:03.623Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-16T14:14:24.385Z"},"containers":{"cna":{"title":"Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root","descriptions":[{"lang":"en","value":"Incus is a system container and virtual machine manager. Prior to version 7.3.0, a malicious image containing a `metadata.yaml` symlink pointing to an arbitrary host path allows an authenticated Incus user to read or overwrite any file on the host as root via the instance metadata API. The `exec-output` and `templates/` paths were patched in a prior release using `Lstat` rejection and `os.OpenRoot` confinement; `metadata.yaml` was not included in either patch and remains exploitable. Version 7.3.0 patches the issue."}],"affected":[{"vendor":"lxc","product":"incus","versions":[{"version":"< 7.3.0","status":"affected"}]}],"references":[{"url":"https://github.com/lxc/incus/security/advisories/GHSA-fmjx-5j3g-997p","name":"https://github.com/lxc/incus/security/advisories/GHSA-fmjx-5j3g-997p","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.9,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-73","lang":"en","description":"CWE-73: External Control of File Name or Path","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-21T14:53:26.109Z"},"source":{"advisory":"GHSA-fmjx-5j3g-997p","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-21T21:00:14.696240Z","id":"CVE-2026-63343","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-21T21:44:03.623Z"}}]}}}