---
title: "CVE-2026-34179: LXD: Update of type field in restricted TLS certificate allows privilege escalation to cluster admin"
url: https://erroneo.us/security/cve/CVE-2026-34179/
description: "CVE-2026-34179 (github.com/canonical/lxd (Go)): In Canonical LXD versions 4.12 through 6.7, the doCertificateUpdate function in lxd/certificates.go does not…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-04-09
date_modified: 2026-04-10
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-34179"
kev: false
cvss: 9.1
epss: 0.00419
license: All rights reserved. Quote with attribution and a link.
---

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

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4% , percentile 35: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 35% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (high (admin)). Exposure depends on who can log in.
- Only applies if your dependency tree includes github.com/canonical/lxd (Go) >= 0.0.0-20210305023314-538ac3df036e, <= 0.0.0-20260226085519-736f34afb267, no fixed version listed . Check your lockfile, including transitive dependencies.

## What it is

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

- Go `github.com/canonical/lxd` >= 0.0.0-20210305023314-538ac3df036e, <= 0.0.0-20260226085519-736f34afb267 → fixed: none listed

## Affected products (CVE record)

- Canonical lxd: 4.12.0 < 5.0.7, 5.1.0 < 5.21.5, 6.0.0 < 6.8.0

## Severity

- canonical CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.1 `CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.42% probability of exploitation activity in the next 30 days; percentile 35.

## Sources

- [Update of type field in restricted TLS certificate allows privilege escalation to cluster admin](https://github.com/canonical/lxd/security/advisories/GHSA-c3h3-89qf-jqm5)
- [Improve validation on certificate edit](https://github.com/canonical/lxd/pull/17936)
- [GitHub Advisory GHSA-c3h3-89qf-jqm5](https://github.com/advisories/GHSA-c3h3-89qf-jqm5)
- [CVE.org record CVE-2026-34179](https://www.cve.org/CVERecord?id=CVE-2026-34179)
- [NVD entry CVE-2026-34179](https://nvd.nist.gov/vuln/detail/CVE-2026-34179)

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Source page: https://erroneo.us/security/cve/CVE-2026-34179/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt