Vulnerability in Red Hat Enterprise Linux 10

[ Why it matters ]Priority signals

• Public proof-of-concept exploit exists (CISA SSVC)

[ Description ]Official 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.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund27 Sep 2026WID-SEC-2026-3598

  QEMU: Vulnerability allows arbitrary code execution with user rights Translated from German

  CVE-2026-93834

[ References ]References

• access.redhat.com/security/cve/CVE-2026-93834
• bugzilla.redhat.com/show_bug.cgi
• gitlab.com/qemu-project/qemu/-/work_items/4491