Incus: Project restriction `restricted.containers.privilege=isolated` bypassable by omitting `security.idmap.isolated`
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-863.
Summary
Incus is a system container and virtual machine manager. Prior to version 7.3.0, project-level enforcement of `restricted.containers.privilege=isolated` can be trivially bypassed, allowing a user to create a non-isolated (shared host idmap) container in a project that is configured to forbid them. The restriction only rejects an explicitly set `security.idmap.isolated=false` (or empty) and fails to enforce anything when the key is omitted entirely. Because an unset `security.idmap.isolated` defaults to `false` (non-isolation), a user simply leaves the key out and obtains exactly the container state the restriction is meant to forbid. This defeats the tenant-isolation guarantee the restriction exists to provide. Containers in the project share the host uid/gid map instead of receiving unique, non-overlapping ranges, weakening the isolation boundary between co-tenant containers and the host. Version 7.3.0 patches the issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA incus (lxc) Fixed in 7.3.0
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-62313
References
More lxc vulnerabilities
- TI-2019-04061 runc through 1.0-rc6, as used in Docker before 18.09.2 and other products, allows… CVSS 3.1HIGH 8.6
- TI-2026-45063 Incus vulnerable to root RCE via image backup.yaml symlink CVSS 3.1CRITICAL 9.9
- TI-2026-44978 Incus: Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge CVSS 3.1CRITICAL 9.9
- TI-2026-36039 Incus has an arbitrary file write on its client due to trusted image hash CVSS 3.1CRITICAL 9.9
- TI-2026-36024 Incus has an arbitrary file write via path traversal in S3 multipart upload CVSS 3.1CRITICAL 9.9
- TI-2026-36022 Incus has a restricted project bypass leading to arbitrary command execution CVSS 3.1CRITICAL 9.9
Sources
- CVE-2026-62313 · CVE Program
- CVE-2026-62313 · NVD
- FIRST EPSS
- CVE-2026-62313 · Red Hat security data · CC BY 4.0
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