CVE-2026-93834

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.

CVSS 3.1

8.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS

0.4% chance of exploitation in the next 30 days; higher than 34% of CVEs (scores of 2026-10-25)

CWE

CWE-416

Published

2026-09-25

Modified

2026-09-29

Record from

the NVD, synced 2026-10-19

References

• https://access.redhat.com/security/cve/CVE-2026-93834
• https://bugzilla.redhat.com/show_bug.cgi?id=2537939
• https://gitlab.com/qemu-project/qemu/-/work_items/4491
• https://gitlab.com/qemu-project/qemu/-/work_items/4491

Check your stackJSON