CVE-2026-62420: Cross-project cluster migration bypasses project restrictions via cluster notification flag

Severity: critical (CVSS 9.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-08-12 · updated 2026-10-24
Weakness: CWE-863

Description

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. An attacker can exploit this to introduce disallowed instance configurations into a restricted project.

Affected products

Canonical LXD: from 5.0.0 before 5.0.8; from 5.1 before 5.21.6; from 6.0 before 6.10 — fixed in 5.0.8, 5.21.6, 6.10

How to fix

Upgrade to a fixed version: Canonical LXD 5.0.8, 5.21.6, 6.10. Check the vendor advisory for mitigations.

References

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