by Kastro
Paper/Archive/CVE-2026-34179

CVE-2026-34179

Canonical lxd — Update of type field in restricted TLS certificate allows privilege escalation to cluster admin

EPSS 0.3%public exploitCVSS 9.1
critical.is priorityof 100
41
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 19.8.198 × 204.0Exploit: SSVC poc+1010.0SSVC exploitation: poc+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
lxd4.12.0 – < 5.0.75.0.7CNA
lxd5.1.0 – < 5.21.55.21.5CNA
lxd6.0.0 – < 6.8.06.8.0CNA

Scores by source

canonical (CNA)9.1CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: poc · Automatable: no · Technical impact: total

References

exploitgithub.com/canonical/lxd/security/advisories/GHSA-c3h3-89qf-jqm5patchgithub.com/canonical/lxd/pull/17936