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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| Red Hat | Red Hat Enterprise Linux 6 | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — |
| Red Hat | Red Hat Enterprise Linux for NVIDIA 26 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — |
| Red Hat | Red Hat OpenStack Platform 13 (Queens) | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | qemu | 1:11.1.2+ds-1 | — |
| Debian 13 | qemu | No fix yet | — |
| Debian 12 | qemu | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | qemu +1 | No fix yet | — |
| Ubuntu 26.04 LTS | qemu +1 | No fix yet | — |
| Ubuntu 24.04 LTS | qemu | No fix yet | — |
| Ubuntu 22.04 LTS | qemu | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | qemu | No fix yet | — |
| Ubuntu Pro 18.04 LTS | qemu | No fix yet | — |
| Ubuntu Pro 16.04 LTS | qemu | No fix yet | — |
| Ubuntu Pro 14.04 LTS | qemu | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | qemu +1 | 10.0.13-160000.2.1 | SUSE-SU-2026:24159-1 |
| SLES 16.0 | qemu +1 | 10.0.13-160000.2.1 | SUSE-SU-2026:24159-1 |
| SLE Micro 6.2 | qemu | 10.0.13-160000.2.1 | SUSE-SU-2026:24115-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | qemu | 11.1.1-2.1 | openSUSE-SU-2026:12049-1 |
| openSUSE Leap 16.0 | qemu +1 | 10.0.13-160000.2.1 | openSUSE-SU-2026:22047-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | qemu +18 | 2:11.0.0-4.amzn2023 | ALAS2023-2026-3241 |
| Amazon Linux 2 | qemu +26 | 10:3.1.0-8.amzn2.0.29 | ALAS2-2026-4027 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | qemu | 10.1.0-2 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
suominen/CVE-2026-93834 ★ 2 · Sep 26, 2026
Tracking the QEMU CVE-2026-93834 9pfs fid-path use-after-free guest-to-host escape
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 7
- ALAS2023-2026-3241 Important: qemu security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 26, 2026
- ALAS2-2026-4027 Important: qemu security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 26, 2026
- WID-SEC-2026-3598 QEMU: Schwachstelle ermöglicht Ausführen von beliebigem Programmcode mit Benutzerrechten BSI CERT-Bund (WID) · Oct 25, 2026
- openSUSE-SU-2026:22047-1 Security update for qemu SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:24159-1 Security update for qemu SUSE / openSUSE Security Updates · Oct 16, 2026
- SUSE-SU-2026:24115-1 Security update for qemu SUSE / openSUSE Security Updates · Oct 10, 2026
- openSUSE-SU-2026:12049-1 qemu-11.1.1-2.1 on GA media SUSE / openSUSE Security Updates · Oct 5, 2026