{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-49238","assignerOrgId":"cc1ad9ee-3454-478d-9317-d3e869d708bc","state":"PUBLISHED","assignerShortName":"canonical","dateReserved":"2026-05-28T12:03:02.295Z","datePublished":"2026-05-28T13:22:25.529Z","dateUpdated":"2026-05-28T14:24:22.829Z"},"containers":{"cna":{"title":"SFTP Server VM Escape in Canonical Multipass","problemTypes":[{"descriptions":[{"lang":"en","cweId":"CWE-22","description":"Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","type":"CWE"}]}],"affected":[{"vendor":"Canonical","product":"Multipass","versions":[{"status":"affected","version":"0","lessThan":"1.16.3","versionType":"semver"}],"defaultStatus":"unaffected"}],"descriptions":[{"lang":"en","value":"An issue was discovered in Canonical Multipass before version 1.16.3. The host-side SFTP server component (sshfs_server), which executes with root privileges on the host, contains a path containment bypass vulnerability within its validate_path function in src/sshfs_mount/sftp_server.cpp. The function performs a plain string prefix comparison on requested paths without path separator validation or dot-dot (..) normalization. A local attacker with root privileges inside a guest virtual machine can bypass the FUSE layer by injecting raw SFTP frames (such as an SSH_FXP_OPEN request) directly into the sshfs_server process stdin/stdout pipes via procfs. By supplying a path containing directory traversal sequences that match the allowed mount prefix, the attacker can force the host-side root process to resolve the traversal and open files outside the designated mount boundary. This allows a guest-side user to read arbitrary files on the host filesystem, resulting in a virtual machine escape."}],"references":[{"url":"https://github.com/canonical/multipass/security/advisories/GHSA-rhp2-23c4-r34w","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"CHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"NONE","baseSeverity":"HIGH","baseScore":8.4,"vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"}}],"source":{"discovery":"EXTERNAL"},"providerMetadata":{"orgId":"cc1ad9ee-3454-478d-9317-d3e869d708bc","shortName":"canonical","dateUpdated":"2026-05-28T13:22:25.529Z"}},"adp":[{"references":[{"url":"https://github.com/canonical/multipass/security/advisories/GHSA-rhp2-23c4-r34w","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-28T14:23:55.283642Z","id":"CVE-2026-49238","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-05-28T14:24:22.829Z"}}]}}