CVE-2026-34178: In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml i

This month

CRITICAL 9.1UPGRADE

CVE-2026-34178 is a critical-severity flaw (CVSS 9.1) affecting lxd. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml in the supplied tar archive but creates the instance from backup/container/backup.yaml, a separate file in the same archive that is never checked against project restrictions. An authenticated remote attacker with instance-creation permission in a restricted project can craft a backup archive where backup.yaml carries restricted settings s

Why this priority

Critical severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	High
User interaction	None
EPSS exploit chance	0.4% (top 64%)
CISA exploited list	No
Weakness	CWE-20
Published	2026-04-09
Last modified	2026-10-26

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

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-09 10:16 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

canonical lxd UPGRADE

Affected: >= 4.12 and <= 5.0.6 · >= 5.21.0 and <= 5.21.4 · >= 6.0 and <= 6.7

Fixed in: newer than 6.7

Safe to downgrade to: a release before 4.12

1. Check installed version

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

2. UPGRADE to newer than 6.7 (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 4.12 (Debian / Ubuntu)

apt-cache madison lxd sudo apt install lxd=<VERSION_BEFORE_4.12> 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_4.12> 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.

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.

Quick answers

How do I fix CVE-2026-34178?

lxd: upgrade to newer than 6.7. Exact commands for each OS are on this page.

Is CVE-2026-34178 being exploited?

CVE-2026-34178 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-34178 affect?

CVE-2026-34178 affects lxd. Severity is critical (CVSS 9.1). In Canonical LXD before 6.8, the backup import path validates project restrictions against backup/index.yaml in the supplied tar archive but creates the instance from backup/container/backup.yaml, a separate file in the same archive that is

How urgent is CVE-2026-34178?

Priority 46/100. Critical severity; Public exploit reference

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References

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