CVE-2026-63297

Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge

State
Published
Severity
9.9 Critical
Published
Aug 12, 2026
Updated
Aug 13, 2026
Reserved
Jul 16, 2026

Read the record on cve.org

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.

Scores

CVSSScoreVectorSource
3.19.9 CriticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hcanonical

Weaknesses

  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
  • CWE-863 Incorrect Authorization

Affected Products

ProductVersions
LXDCanonical
  • 5.0.0 to before 5.0.8Affected
  • 5.21.0 to before 5.21.6Affected

References

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