CVE-2026-49238

8.4 HIGH 0.5% exploit odds Fix listed Disclosure Server

What it is

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.

At a glance

Exploitability: Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering.
Exploit odds: 0.5% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-05-28 14:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-10-14 20:10 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.5% in the next 30 days (EPSS).
Severity: 8.4 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-05-28 14:16 UTC
Last modified: 2026-10-14 20:10 UTC
Exploit probability: 0.5% · EPSS, next 30 days
Weakness: CWE-22 · Path traversal
Record status: Analyzed

Affected

Canonical Multipass < 1.16.3

Attack profile CVSS 3.1 · 8.4

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None
Scope: Changed
Confidentiality: High
Integrity: High
Availability: None

Raw vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

Is it in your code?

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Read https://cve-list.com/agent/cve/CVE-2026-49238.md and follow it. Check whether this project is affected by CVE-2026-49238. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record