CVE-2026-49238 Detail
Received
This CVE record has recently been published to the CVE List and has been included within the NVD dataset. DescriptionAn 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. Metrics
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CVSS 4.0 Severity and Vector Strings:
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Weakness Enumeration
Quick InfoCVE Dictionary Entry:CVE-2026-49238 NVD Published Date: 05/28/2026 NVD Last Modified: 05/28/2026 Source: Canonical Ltd. |
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