Vulnerability · Published Apr 9, 2026 · Assigned by canonical
CVE-2026-34179Update of type field in restricted TLS certificate allows privilege escalation to cluster admin
Critical 9.1
In plain English
A critical-severity security flaw in lxd from Canonical. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)9.1Critical
Exploit odds (30 days)0.3%top 79.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known
Official description
In Canonical LXD versions 4.12 through 6.7, the doCertificateUpdate function in lxd/certificates.go does not validate the Type field when handling PUT/PATCH requests to /1.0/certificates/{fingerprint} for restricted TLS certificate users, allowing a remote authenticated attacker to escalate privileges to cluster admin.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | incus | 6.0.4-2+deb13u6 | DEBIAN-CVE-2026-34179 |
| Debian:14 | incus | 6.0.6-3 | DEBIAN-CVE-2026-34179 |
| Debian:12 | lxd | no fix listed | DEBIAN-CVE-2026-34179 |
| Debian:13 | lxd | 5.0.2+git20231211.1364ae4-9+deb13u5 | DEBIAN-CVE-2026-34179 |
| Go | github.com/canonical/lxd | no fix listed | GHSA-c3h3-89qf-jqm5 |
| Go | github.com/canonical/lxd | no fix listed | GO-2026-5306 |
| Ubuntu:25.10 | incus | no fix listed | UBUNTU-CVE-2026-34179 |
| Ubuntu:26.10 | incus | no fix listed | UBUNTU-CVE-2026-34179 |
Affected products (as reported)
Weakness: CWE-915 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
References
- Update of type field in restricted TLS certificate allows privilege escalation to cluster admin vdb-entry, vendor-advisory
- Improve validation on certificate edit patch, issue-tracking