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

Badges

👾 Exploit Exists🟡 Public PoC

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.

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-93834
Created by suominen

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

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

.