CVE-2026-62420: An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project securit

This month

CRITICAL 9.9UPGRADE

CVE-2026-62420 is a critical-severity flaw (CVSS 9.9) affecting lxd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project security restrictions during cross-project instance migrations. When moving an instance cross-project to a different cluster member via POST /1.0/instances/{name} with migration: true, project: <target>, and target: <member>, the destination node skips all project restriction checks because the request arrives as an internal cluster notification

Why this priority

Critical severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.9 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 55%)
CISA exploited list	No
Weakness	CWE-863
Published	2026-08-12
Last modified	2026-10-23

Publisher (CNA): Canonical Ltd. · Vendor: canonical

Am I affected?

Timeline

2026-08-12 20:17 UTCPublished CVE record published
2026-10-23 19:10 UTCUpdated Record last modified

canonical lxd UPGRADE

Affected: >= 5.0.0 and < 5.0.8 · >= 5.1 and < 5.21.6 · >= 6.0 and < 6.10

Fixed in: 5.0.8, 5.21.6, 6.10

Safe to downgrade to: a release before 5.0.0

1. Check installed version

apt-cache policy lxd || rpm -q lxd || lxd --version

2. UPGRADE to 5.0.8 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade lxd

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade lxd

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 5.0.0 (Debian / Ubuntu)

apt-cache madison lxd sudo apt install lxd=<VERSION_BEFORE_5.0.0> sudo apt-mark hold lxd

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list lxd sudo dnf downgrade lxd-<VERSION_BEFORE_5.0.0> sudo dnf versionlock add lxd

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · rubygem-eventmachine · FIXED · 1.2.7-37.fc46 · FEDORA-2026-7194c202a2 · source

sudo dnf upgrade --advisory=FEDORA-2026-7194c202a2

Debian 12 · lxd · NO FIX YET

Debian 13 · lxd · NO FIX YET

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: github.com/canonical/lxd/security/advisories/GHSA-v9wr-9r7q-fh4g

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

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References

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