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Fencer Vulns
high 8.2

CVE-2021-3546 json

An out-of-bounds write vulnerability was found in the virtio vhost-user GPU device (vhost-user-gpu) of QEMU in versions up to and including…

published 2021-06-02 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-26857

cvss
8.2
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

An out-of-bounds write vulnerability was found in the virtio vhost-user GPU device (vhost-user-gpu) of QEMU in versions up to and including 6.0. The flaw occurs while processing the 'VIRTIO_GPU_CMD_GET_CAPSET' command from the guest. It could allow a privileged guest user to crash the QEMU process on the host, resulting in a denial of service condition, or potential code execution with the privileges of the QEMU process.

Patch / fix

  • qemu Debian 14, Debian 13, Debian 12 1:6.1+dfsg-1

debian advisories DEBIAN-CVE-2021-3546

  • qemu Ubuntu 20.04 LTS 1:4.2-3ubuntu6.17
  • qemu Ubuntu 22.04 LTS 1:6.2+dfsg-2ubuntu5

ubuntu advisories UBUNTU-CVE-2021-3546

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • qemu SLE Module for Server Applications 15 SP3, SLE Module for Basesystem 15 SP3 5.2.0-20.1
  • qemu SLE Module for Server Applications 15 SP2, SLE Module for Basesystem 15 SP2, SLE Micro 5.0 4.2.1-11.22.1

suse advisories SUSE-SU-2021:2213-1SUSE-SU-2021:2212-1

  • qemu openSUSE Tumbleweed 6.1.0-32.1
  • qemu openSUSE Leap 15.2 4.2.1-lp152.9.16.2
  • qemu-testsuite openSUSE Leap 15.2 4.2.1-lp152.9.16.7
  • qemu-linux-user openSUSE Leap 15.2 4.2.1-lp152.9.16.1
  • qemu openSUSE Leap 15.3 5.2.0-20.1

opensuse advisories openSUSE-SU-2024:11287-1openSUSE-SU-2021:1043-1openSUSE-SU-2021:2213-1

  • qemu Alpine 3.24, Alpine 3.23, Alpine 3.22 +6 more 6.1.0-r0

alpine advisories ALPINE-CVE-2021-3546

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-3546 updated cvss 8.2

QEMU: vhost-user-gpu: out-of-bounds write in virgl_cmd_get_capset()

  • Red Hat Enterprise Linux 8 Advanced Virtualization qemu-img, qemu-kvm, qemu-kiwi, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, +9 more
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 6 qemu-img, qemu-kvm, qemu-kvm-tools, qemu-guest-agent, qemu-guest-agent-win32 Red Hat Enterprise Linux 7 qemu-img, qemu-kvm, libcacard, qemu-img-ma, qemu-kvm-ma, qemu-kvm-rhev, +6 more Red Hat Enterprise Linux 8 qemu-img, qemu-kvm, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, qemu-guest-agent, +8 more Red Hat Enterprise Linux 8 Advanced Virtualization qemu-img, qemu-kvm, qemu-kiwi, qemu-kvm-core, qemu-kvm-tests, qemu-kvm-common, +9 more Red Hat Enterprise Linux 9 qemu-img, qemu-kvm, qemu-kvm-core, qemu-kvm-tools, qemu-pr-helper, qemu-kvm-common, +16 more Red Hat OpenStack Platform 10 (Newton) qemu-img-rhev, qemu-kvm-rhev, qemu-kvm-tools-rhev, qemu-kvm-common-rhev
    +1 more products
    Red Hat OpenStack Platform 13 (Queens) qemu-img-rhev, qemu-kvm-rhev, qemu-kvm-tools-rhev, qemu-kvm-common-rhev
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.46% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.2 CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • n/a QEMU

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.