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Fencer Intel
medium 5.5

CVE-2026-63623 json

Libvirt: information disclosure via world-readable storage volume images during clone/convert

published 3mo ago modified 6d ago also EUVD-2026-55675

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits
0
none known

Summary

A flaw was found in libvirt. During storage volume clone or convert operations, newly created volume images were temporarily world-readable. This was caused by the `qemu-img` utility running with overly permissive file creation settings, allowing any local user to read the full guest disk contents. This vulnerability could lead to sensitive information disclosure from guest virtual machines.

Patch / fix

  • libvirt Debian 13 11.3.0-3+deb13u3
  • libvirt Debian 14 12.6.0-1

debian advisories DEBIAN-CVE-2026-63623

  • libvirt Ubuntu 22.04 LTS 8.0.0-1ubuntu7.19
  • libvirt Ubuntu 24.04 LTS 10.0.0-2ubuntu8.16
  • libvirt Ubuntu 26.04 LTS 12.0.0-1ubuntu5.3
  • libvirt-hwe Ubuntu 26.04 LTS 12.0.0-1ubuntu5.5
  • libvirt Ubuntu Pro 14.04 LTS 1.2.2-0ubuntu13.1.28+esm2
  • libvirt Ubuntu Pro 16.04 LTS 1.3.1-1ubuntu10.31+esm1
  • libvirt Ubuntu Pro 18.04 LTS 4.0.0-1ubuntu8.21+esm1
  • libvirt Ubuntu Pro 20.04 LTS 6.0.0-0ubuntu8.20+esm1

ubuntu advisories UBUNTU-CVE-2026-63623

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

  • libvirt SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 9.0.0-150500.6.29.1
  • libvirt SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +3 more 8.0.0-150400.7.17.1
  • libvirt SLE Module for Server Applications 15 SP7, SLE Module for Basesystem 15 SP7 11.0.0-150700.4.27.1
  • libvirt SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 11.4.0-160000.5.1
  • libvirt Linux Micro 6.0 10.0.0-5.1
  • libvirt Linux Micro 6.1 10.0.0-slfo.1.1_3.1
  • libvirt SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 5.1.0-13.48.1
  • libvirt SLES for SAP 15 SP6, SLES 15 SP6-LTSS 10.0.0-150600.8.18.1

suse advisories SUSE-SU-2026:4141-1SUSE-SU-2026:4010-1SUSE-SU-2026:4009-1SUSE-SU-2026:4004-1SUSE-SU-2026:3939-1SUSE-SU-2026:23460-1

  • libvirt openSUSE Leap 16.0 11.4.0-160000.5.1
  • libvirt openSUSE Tumbleweed 12.6.0-1.1

opensuse advisories openSUSE-SU-2026:21738-1openSUSE-SU-2026:11455-1

  • libvirt Azure Linux 3.0 11.9.0-1

azure linux advisories AZL-95613

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-63623 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2026-63623 updated cvss 5.5

libvirt: Information disclosure via world-readable storage volume images during clone/convert

  • Red Hat Enterprise Linux 6 libvirt, libvirt-client, libvirt-python, libvirt-lock-sanlock Red Hat Enterprise Linux 7 libvirt, libvirt-nss, libvirt-libs, libvirt-admin, libvirt-client, libvirt-daemon, +24 more Red Hat Enterprise Linux 8 libvirt, libvirt-nss, libvirt-libs, libvirt-admin, libvirt-client, libvirt-daemon, +22 more Red Hat Enterprise Linux 9 libvirt, libvirt-nss, libvirt-libs, libvirt-client, libvirt-daemon, libvirt-ssh-proxy, +25 more Red Hat Enterprise Linux 10 libvirt
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux for NVIDIA 26 libvirt
    affected: workaround, no fix planned “Out of support scope”

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

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3mo ago

Exploit prediction

0.10% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected products

  • 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

Classification

Weakness
  • CWE-732 Incorrect Permission Assignment for Critical Resource

References

Sources

Fencer Intel 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.