Use-After-Free Vulnerability in QEMU's 9pfs Subsystem
CVE-2026-93834

8.8HIGH

Key Information:

Vendor

Red Hat
Status
Red Hat Enterprise Linux 10
Red Hat Enterprise Linux 6
Red Hat Enterprise Linux 7
Red Hat Enterprise Linux 8
Vendor
CVE Published:
25 September 2026

What is CVE-2026-93834?

A use-after-free vulnerability in QEMU's 9pfs subsystem poses significant risks by allowing malicious users to exploit a race condition between the main thread and worker thread during the processing of concurrent Tlcreate and Twalk requests. This flaw can enable a crafted fid path to bypass directory traversal restrictions, leading to unauthorized access and manipulation of host files, thus facilitating VM escapes that compromise the host system.

References

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

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.