{"schemaVersion":3,"id":"CVE-2026-49238","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"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.","dates":{"published":"2026-05-28T13:22:25.529Z","modified":"2026-05-28T14:24:22.829Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":8.4,"severity":"high","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":8.4,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":8.4,"severity":"high","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00446,"percentile":0.37462,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":-0.05899999999999994,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.00505},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00446,"percentile":0.37462}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.00505,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00446,"percentile":null},{"date":"2026-10-10T00:00: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1.16.3","eol":null,"hubHref":"/vendor/canonical/multipass"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/canonical/multipass/security/advisories/GHSA-rhp2-23c4-r34w","label":"github.com/canonical/multipass/security/advisories/GHSA-rhp2-23c4-r34w","hostname":"github.com","tags":["Vendor Advisory","Exploit","Third Party Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-05-28T13:22:25.529Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-05-28T14:24:22.829Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":44,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T19:59:03.139Z","stale":false,"partial":false}}