Skip to main content
Threat Radar animated logo

A use-after-free vulnerability was found in QEMU's 9pfs subsystem. (CVE-2026-93834)

0
Medium
VulnerabilityCVE-2026-93834gcveosvubuntu-cve-2026-93834cve-2026-93834ubuntu-pro-14-04-ltsubuntu-pro-16-04-ltsubuntu-pro-18-04-ltsubuntu-pro-20-04-ltsubuntu-22-04-ltsubuntu-24-04-ltsubuntu-26-10ubuntu-26-04-lts
Published: 09/25/2026 (09/25/2026, 14:17:00 UTC)
Source: GCVE Database
Product: qemu

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.

CVSS v3.1

Score 8.8high

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected software

Ubuntu:Pro:14.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=esm-infra-legacy/trusty
Affected versions
=1.5.0+dfsg-3ubuntu5=1.5.0+dfsg-3ubuntu6=1.6.0+dfsg-2ubuntu1=1.6.0+dfsg-2ubuntu2=1.6.0+dfsg-2ubuntu3=1.6.0+dfsg-2ubuntu4=1.7.0+dfsg-2ubuntu1=1.7.0+dfsg-2ubuntu2=1.7.0+dfsg-2ubuntu3=1.7.0+dfsg-2ubuntu4=1.7.0+dfsg-2ubuntu5=1.7.0+dfsg-2ubuntu7=1.7.0+dfsg-2ubuntu8=1.7.0+dfsg-2ubuntu9=1.7.0+dfsg-3ubuntu1~ppa1=1.7.0+dfsg-3ubuntu1=1.7.0+dfsg-3ubuntu2=1.7.0+dfsg-3ubuntu3=1.7.0+dfsg-3ubuntu4=1.7.0+dfsg-3ubuntu5=1.7.0+dfsg-3ubuntu6=1.7.0+dfsg-3ubuntu7=2.0.0~rc1+dfsg-0ubuntu1=2.0.0~rc1+dfsg-0ubuntu2=2.0.0~rc1+dfsg-0ubuntu3=2.0.0~rc1+dfsg-0ubuntu3.1=2.0.0+dfsg-2ubuntu1=2.0.0+dfsg-2ubuntu1.1=2.0.0+dfsg-2ubuntu1.2=2.0.0+dfsg-2ubuntu1.3=2.0.0+dfsg-2ubuntu1.5=2.0.0+dfsg-2ubuntu1.6=2.0.0+dfsg-2ubuntu1.7=2.0.0+dfsg-2ubuntu1.8=2.0.0+dfsg-2ubuntu1.9=2.0.0+dfsg-2ubuntu1.10=2.0.0+dfsg-2ubuntu1.11=2.0.0+dfsg-2ubuntu1.13=2.0.0+dfsg-2ubuntu1.14=2.0.0+dfsg-2ubuntu1.15=2.0.0+dfsg-2ubuntu1.16=2.0.0+dfsg-2ubuntu1.17=2.0.0+dfsg-2ubuntu1.18=2.0.0+dfsg-2ubuntu1.19=2.0.0+dfsg-2ubuntu1.20=2.0.0+dfsg-2ubuntu1.21=2.0.0+dfsg-2ubuntu1.22=2.0.0+dfsg-2ubuntu1.24=2.0.0+dfsg-2ubuntu1.25=2.0.0+dfsg-2ubuntu1.26=2.0.0+dfsg-2ubuntu1.27=2.0.0+dfsg-2ubuntu1.28=2.0.0+dfsg-2ubuntu1.29=2.0.0+dfsg-2ubuntu1.30=2.0.0+dfsg-2ubuntu1.31=2.0.0+dfsg-2ubuntu1.32=2.0.0+dfsg-2ubuntu1.33=2.0.0+dfsg-2ubuntu1.34=2.0.0+dfsg-2ubuntu1.35=2.0.0+dfsg-2ubuntu1.36=2.0.0+dfsg-2ubuntu1.38=2.0.0+dfsg-2ubuntu1.39=2.0.0+dfsg-2ubuntu1.40=2.0.0+dfsg-2ubuntu1.41=2.0.0+dfsg-2ubuntu1.42=2.0.0+dfsg-2ubuntu1.43=2.0.0+dfsg-2ubuntu1.44=2.0.0+dfsg-2ubuntu1.45=2.0.0+dfsg-2ubuntu1.46=2.0.0+dfsg-2ubuntu1.47=2.0.0+dfsg-2ubuntu1.47+esm1=2.0.0+dfsg-2ubuntu1.47+esm2=2.0.0+dfsg-2ubuntu1.47+esm3=2.0.0+dfsg-2ubuntu1.47+esm4=2.0.0+dfsg-2ubuntu1.47+esm6
Ubuntu:Pro:16.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=esm-infra-legacy/xenial
Affected versions
=1:2.3+dfsg-5ubuntu9=1:2.3+dfsg-5ubuntu10=1:2.4+dfsg-4ubuntu1=1:2.4+dfsg-4ubuntu2=1:2.4+dfsg-4ubuntu3=1:2.4+dfsg-5ubuntu3=1:2.5+dfsg-1ubuntu2=1:2.5+dfsg-1ubuntu3=1:2.5+dfsg-1ubuntu4=1:2.5+dfsg-1ubuntu5=1:2.5+dfsg-5ubuntu1=1:2.5+dfsg-5ubuntu2=1:2.5+dfsg-5ubuntu4=1:2.5+dfsg-5ubuntu6=1:2.5+dfsg-5ubuntu7=1:2.5+dfsg-5ubuntu10=1:2.5+dfsg-5ubuntu10.1=1:2.5+dfsg-5ubuntu10.2=1:2.5+dfsg-5ubuntu10.3=1:2.5+dfsg-5ubuntu10.4=1:2.5+dfsg-5ubuntu10.5=1:2.5+dfsg-5ubuntu10.6=1:2.5+dfsg-5ubuntu10.7=1:2.5+dfsg-5ubuntu10.8=1:2.5+dfsg-5ubuntu10.9=1:2.5+dfsg-5ubuntu10.10=1:2.5+dfsg-5ubuntu10.11=1:2.5+dfsg-5ubuntu10.13=1:2.5+dfsg-5ubuntu10.14=1:2.5+dfsg-5ubuntu10.15=1:2.5+dfsg-5ubuntu10.16=1:2.5+dfsg-5ubuntu10.20=1:2.5+dfsg-5ubuntu10.21=1:2.5+dfsg-5ubuntu10.22=1:2.5+dfsg-5ubuntu10.24=1:2.5+dfsg-5ubuntu10.25=1:2.5+dfsg-5ubuntu10.26=1:2.5+dfsg-5ubuntu10.28=1:2.5+dfsg-5ubuntu10.29=1:2.5+dfsg-5ubuntu10.30=1:2.5+dfsg-5ubuntu10.31=1:2.5+dfsg-5ubuntu10.32=1:2.5+dfsg-5ubuntu10.33=1:2.5+dfsg-5ubuntu10.34=1:2.5+dfsg-5ubuntu10.35=1:2.5+dfsg-5ubuntu10.36=1:2.5+dfsg-5ubuntu10.37=1:2.5+dfsg-5ubuntu10.38=1:2.5+dfsg-5ubuntu10.39=1:2.5+dfsg-5ubuntu10.40=1:2.5+dfsg-5ubuntu10.41=1:2.5+dfsg-5ubuntu10.42=1:2.5+dfsg-5ubuntu10.43=1:2.5+dfsg-5ubuntu10.44=1:2.5+dfsg-5ubuntu10.45=1:2.5+dfsg-5ubuntu10.46=1:2.5+dfsg-5ubuntu10.47=1:2.5+dfsg-5ubuntu10.48=1:2.5+dfsg-5ubuntu10.49=1:2.5+dfsg-5ubuntu10.51=1:2.5+dfsg-5ubuntu10.51+esm1=1:2.5+dfsg-5ubuntu10.51+esm2=1:2.5+dfsg-5ubuntu10.51+esm3=1:2.5+dfsg-5ubuntu10.51+esm4
Ubuntu:Pro:18.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=esm-infra/bionic
Affected versions
=1:2.10+dfsg-0ubuntu3=1:2.10+dfsg-0ubuntu4=1:2.10+dfsg-0ubuntu5=1:2.11+dfsg-1ubuntu1=1:2.11+dfsg-1ubuntu2=1:2.11+dfsg-1ubuntu4=1:2.11+dfsg-1ubuntu5=1:2.11+dfsg-1ubuntu6=1:2.11+dfsg-1ubuntu7=1:2.11+dfsg-1ubuntu7.1=1:2.11+dfsg-1ubuntu7.2=1:2.11+dfsg-1ubuntu7.3=1:2.11+dfsg-1ubuntu7.4=1:2.11+dfsg-1ubuntu7.5=1:2.11+dfsg-1ubuntu7.6=1:2.11+dfsg-1ubuntu7.7=1:2.11+dfsg-1ubuntu7.8=1:2.11+dfsg-1ubuntu7.9=1:2.11+dfsg-1ubuntu7.10=1:2.11+dfsg-1ubuntu7.12=1:2.11+dfsg-1ubuntu7.13=1:2.11+dfsg-1ubuntu7.14=1:2.11+dfsg-1ubuntu7.15=1:2.11+dfsg-1ubuntu7.17=1:2.11+dfsg-1ubuntu7.18=1:2.11+dfsg-1ubuntu7.19=1:2.11+dfsg-1ubuntu7.20=1:2.11+dfsg-1ubuntu7.21=1:2.11+dfsg-1ubuntu7.22=1:2.11+dfsg-1ubuntu7.23=1:2.11+dfsg-1ubuntu7.25=1:2.11+dfsg-1ubuntu7.26=1:2.11+dfsg-1ubuntu7.27=1:2.11+dfsg-1ubuntu7.28=1:2.11+dfsg-1ubuntu7.29=1:2.11+dfsg-1ubuntu7.31=1:2.11+dfsg-1ubuntu7.32=1:2.11+dfsg-1ubuntu7.33=1:2.11+dfsg-1ubuntu7.34=1:2.11+dfsg-1ubuntu7.35=1:2.11+dfsg-1ubuntu7.36=1:2.11+dfsg-1ubuntu7.37=1:2.11+dfsg-1ubuntu7.38=1:2.11+dfsg-1ubuntu7.39=1:2.11+dfsg-1ubuntu7.40=1:2.11+dfsg-1ubuntu7.41=1:2.11+dfsg-1ubuntu7.42=1:2.11+dfsg-1ubuntu7.42+esm1=1:2.11+dfsg-1ubuntu7.42+esm2=1:2.11+dfsg-1ubuntu7.42+esm5=1:2.11+dfsg-1ubuntu7.42+esm6
Ubuntu:Pro:20.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=esm-infra/focal
Affected versions
=1:4.0+dfsg-0ubuntu9=1:4.0+dfsg-0ubuntu10=1:4.2-1ubuntu1=1:4.2-1ubuntu2=1:4.2-3ubuntu1=1:4.2-3ubuntu2=1:4.2-3ubuntu3=1:4.2-3ubuntu4=1:4.2-3ubuntu5=1:4.2-3ubuntu6=1:4.2-3ubuntu6.1=1:4.2-3ubuntu6.2=1:4.2-3ubuntu6.3=1:4.2-3ubuntu6.4=1:4.2-3ubuntu6.5=1:4.2-3ubuntu6.6=1:4.2-3ubuntu6.7=1:4.2-3ubuntu6.8=1:4.2-3ubuntu6.9=1:4.2-3ubuntu6.10=1:4.2-3ubuntu6.11=1:4.2-3ubuntu6.12=1:4.2-3ubuntu6.14=1:4.2-3ubuntu6.15=1:4.2-3ubuntu6.16=1:4.2-3ubuntu6.17=1:4.2-3ubuntu6.18=1:4.2-3ubuntu6.19=1:4.2-3ubuntu6.21=1:4.2-3ubuntu6.23=1:4.2-3ubuntu6.24=1:4.2-3ubuntu6.25=1:4.2-3ubuntu6.26=1:4.2-3ubuntu6.27=1:4.2-3ubuntu6.28=1:4.2-3ubuntu6.29=1:4.2-3ubuntu6.30=1:4.2-3ubuntu6.30+esm1=1:4.2-3ubuntu6.30+esm2=1:4.2-3ubuntu6.30+esm3
Ubuntu:22.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=jammy
Affected versions
=1:6.0+dfsg-2expubuntu1=1:6.0+dfsg-2expubuntu2=1:6.0+dfsg-2expubuntu4=1:6.2+dfsg-2ubuntu5=1:6.2+dfsg-2ubuntu6=1:6.2+dfsg-2ubuntu6.1=1:6.2+dfsg-2ubuntu6.2=1:6.2+dfsg-2ubuntu6.3=1:6.2+dfsg-2ubuntu6.4=1:6.2+dfsg-2ubuntu6.5=1:6.2+dfsg-2ubuntu6.6=1:6.2+dfsg-2ubuntu6.7=1:6.2+dfsg-2ubuntu6.8=1:6.2+dfsg-2ubuntu6.9=1:6.2+dfsg-2ubuntu6.10=1:6.2+dfsg-2ubuntu6.11=1:6.2+dfsg-2ubuntu6.12=1:6.2+dfsg-2ubuntu6.13=1:6.2+dfsg-2ubuntu6.14=1:6.2+dfsg-2ubuntu6.15=1:6.2+dfsg-2ubuntu6.16=1:6.2+dfsg-2ubuntu6.17=1:6.2+dfsg-2ubuntu6.18=1:6.2+dfsg-2ubuntu6.19=1:6.2+dfsg-2ubuntu6.21=1:6.2+dfsg-2ubuntu6.22=1:6.2+dfsg-2ubuntu6.23=1:6.2+dfsg-2ubuntu6.24=1:6.2+dfsg-2ubuntu6.25=1:6.2+dfsg-2ubuntu6.26=1:6.2+dfsg-2ubuntu6.27=1:6.2+dfsg-2ubuntu6.28=1:6.2+dfsg-2ubuntu6.29=1:6.2+dfsg-2ubuntu6.30=1:6.2+dfsg-2ubuntu6.31
Ubuntu:24.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=noble
Affected versions
=1:8.0.4+dfsg-1ubuntu3=1:8.0.4+dfsg-1ubuntu4=1:8.0.4+dfsg-1ubuntu5=1:8.1.3+ds-1ubuntu2=1:8.2.1+ds-1ubuntu1=1:8.2.1+ds-1ubuntu8=1:8.2.1+ds-1ubuntu9=1:8.2.2+ds-0ubuntu1=1:8.2.2+ds-0ubuntu1.2=1:8.2.2+ds-0ubuntu1.4=1:8.2.2+ds-0ubuntu1.5=1:8.2.2+ds-0ubuntu1.6=1:8.2.2+ds-0ubuntu1.7=1:8.2.2+ds-0ubuntu1.8=1:8.2.2+ds-0ubuntu1.9=1:8.2.2+ds-0ubuntu1.10=1:8.2.2+ds-0ubuntu1.11=1:8.2.2+ds-0ubuntu1.12=1:8.2.2+ds-0ubuntu1.13=1:8.2.2+ds-0ubuntu1.14=1:8.2.2+ds-0ubuntu1.15=1:8.2.2+ds-0ubuntu1.16=1:8.2.2+ds-0ubuntu1.17=1:8.2.2+ds-0ubuntu1.18
Ubuntu:26.10more threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=stonking
Affected versions
=1:10.2.1+ds-1ubuntu3=1:10.2.1+ds-1ubuntu6=1:11.0.3+ds-2ubuntu1=1:11.0.3+ds-2ubuntu2
Ubuntu:26.10more threats →ghsa
qemu-hwe
pkg:deb/ubuntu/qemu-hwe?arch=source&distro=stonking
Affected versions
=1:10.2.1+ds-1ubuntu4=1:10.2.1+ds-1ubuntu7=1:10.2.1+ds-1ubuntu8=1:11.0.3+ds-2ubuntu2=1:11.0.3+ds-2ubuntu4
Ubuntu:26.04:LTSmore threats →ghsa
qemu
pkg:deb/ubuntu/qemu?arch=source&distro=resolute
Affected versions
=1:10.1.0+ds-5ubuntu2=1:10.1.0+ds-5ubuntu3=1:10.1.0+ds-5ubuntu4=1:10.1.0+ds-5ubuntu5=1:10.2.1+ds-1ubuntu1=1:10.2.1+ds-1ubuntu2=1:10.2.1+ds-1ubuntu3=1:10.2.1+ds-1ubuntu3.1=1:10.2.1+ds-1ubuntu3.2
Ubuntu:26.04:LTSmore threats →ghsa
qemu-hwe
pkg:deb/ubuntu/qemu-hwe?arch=source&distro=resolute
Affected versions
=1:10.2.1+ds-1ubuntu2=1:10.2.1+ds-1ubuntu4=1:10.2.1+ds-1ubuntu4.2=1:10.2.1+ds-1ubuntu4.3

Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.

Technical Details

Gcve Source
db.gcve.eu
Osv Id
UBUNTU-CVE-2026-93834
Osv Schema Version
1.7.0
Ecosystems
["Ubuntu:Pro:14.04:LTS","Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:26.10","Ubuntu:26.04:LTS"]
Cvss Version
3.1
State
PUBLISHED

Threat ID: 6ad3f51f2cdf04f656658571

Added to database: 10/17/2026, 22:22:23 UTC

Last updated: 10/17/2026, 23:05:03 UTC

Views: 3

Community Reviews

0 reviews

Crowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.

Sort by
Loading community insights…

Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.

Actions

Please log in to the Console to use AI analysis features.

Need more coverage?

Upgrade to Pro Console for AI refresh and higher limits.

For incident response and remediation, OffSeq services can help resolve threats faster.

Latest Threats

Breach by OffSeqOFFSEQFRIENDS — 25% OFF

Check if your credentials are on the dark web

Instant breach scanning across billions of leaked records. Free tier available.

Scan now
OffSeq TrainingCredly Certified

Lead Pen Test Professional

Technical5-day eLearningPECB Accredited
View courses