Update of type field in restricted TLS certificate allows privilege escalation to cluster admin
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Tampering
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-915.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Canonical | lxd | 4.12.0 to before 5.0.7; 5.1.0 to before 5.21.5; 6.0.0 to before 6.8.0 | 5.0.7, 5.21.5, 6.8.0 | Patch available | CNA |
| — | github.com/canonical/lxd (Go) | 0.0.0-20210305023314-538ac3df036e – 0.0.0-20260226085519-736f34afb267 | — | No fix listed | GHSA-c3h3-89qf-jqm5 |
- lxd VendorCanonical Affected 4.12.0 to before 5.0.7; 5.1.0 to before 5.21.5; 6.0.0 to before 6.8.0 Fixed in 5.0.7, 5.21.5, 6.8.0 Patch available CNA
- github.com/canonical/lxd (Go) Vendor— Affected 0.0.0-20210305023314-538ac3df036e – 0.0.0-20260226085519-736f34afb267 Fixed in — No fix listed GHSA-c3h3-89qf-jqm5
Remediation
- Fix · CNA lxd (Canonical) Fixed in 5.0.7, 5.21.5, 6.8.0
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
Canonical lxd 5.0.7, 5.21.5, 6.8.0
3 records Highest priority Priority HIGH 3 HIGH
Other records, highest priority first
- TI-2026-26475 Importing a crafted backup leads to project restriction bypassPriority HIGH 74
- TI-2026-26474 VM lowlevel restriction bypass via raw.apparmor and raw.qemu.confPriority HIGH 74
Timeline
- 2026-10-02 Threatist record created from CVE-2026-34179
- 2026-10-03 Alias added: GHSA-c3h3-89qf-jqm5
References
More Canonical Lxd vulnerabilities
- TI-2026-22659 Authenticated RCE via unsanitized compression_algorithm CVSS 4.0CRITICAL 9.4
- TI-2026-47475 Path traversal via unvalidated instance name in backup tarball restore enables root file write / RCE CVSS 3.1CRITICAL 9.9
- TI-2026-45146 Cross-project instance move bypasses all project restrictions allowing host command execution CVSS 3.1CRITICAL 9.9
- TI-2026-45143 Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge CVSS 3.1CRITICAL 9.9
- TI-2026-45142 Project restriction bypass via instance migration config override CVSS 3.1CRITICAL 9.9
- TI-2026-45140 Root RCE via image backup.yaml symlink CVSS 3.1CRITICAL 9.9
Sources
- CVE-2026-34179 · CVE Program
- CVE-2026-34179 · NVD
- FIRST EPSS
- GHSA-c3h3-89qf-jqm5 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences