CVE-2026-63297
An authorization bypass vulnerability in LXD due to a timing flaw during configuration merging allows an authenticated attacker to bypass target project restrictions during cross-project instance copies.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
An authorization bypass vulnerability in LXD due to a timing flaw during configuration merging allows an authenticated attacker to bypass target project restrictions during cross-project instance copies. When copying an instance to a target project, LXD performs restriction checks before configuration merging is complete, creating a time-of-check to time-of-use (TOCTOU) condition. An attacker can exploit this flaw to copy instances with disallowed high-privilege configurations into restricted projects, bypassing security controls.
- CVSS 3.1
- 9.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-367, CWE-863
- Affected
- canonical/lxd
- Source
- security@ubuntu.com
References
- https://github.com/canonical/lxd/security/advisories/GHSA-v989-qw7w-xvg4Vendor Advisory, Exploit, Mitigation
- https://github.com/canonical/lxd/security/advisories/GHSA-v989-qw7w-xvg4Vendor Advisory, Exploit, Mitigation
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.