CVE-2026-93834

high

Description

A use-after-free vulnerability was found in QEMU's 9pfs subsystem. A race condition between the main thread and a worker thread when processing concurrent Tlcreate and Twalk requests allows a malicious guest user to craft a fid path containing stale heap data, bypassing directory traversal restrictions and escaping the shared directory boundary. This can lead to arbitrary host file read/write and code execution (VM escape) as the QEMU process user.

References

https://gitlab.com/qemu-project/qemu/-/work_items/4491

https://bugzilla.redhat.com/show_bug.cgi?id=2537939

https://access.redhat.com/security/cve/CVE-2026-93834

Details

Source: Mitre, NVD

Published: 2026-09-25

Updated: 2026-09-25

Risk Information

CVSS v2

Base Score: 6.8

Vector: CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C

Severity: Medium

CVSS v3

Base Score: 8.8

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

Severity: High

EPSS

EPSS: 0.00377