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

> Authenticated attackers can escalate privileges to cluster admin by modifying the type field of restricted TLS certificates in LXD.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Apr 2026
- **Updated:** 9 Apr 2026
- **Also known as:** DEBIAN-CVE-2026-34179, GHSA-c3h3-89qf-jqm5, GO-2026-5306, UBUNTU-CVE-2026-34179

## What is CVE-2026-34179?

CVE-2026-34179 is a critical vulnerability in Canonical lxd, published on 9 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### 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.

Weakness: CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes)

## Which versions are affected by CVE-2026-34179?

3 open source packages ship an affected version, including github.com/canonical/lxd. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `github.com/canonical/lxd` | Go | All versions | None |
| `github.com/canonical/lxd` | Go | From 0.0.0-20210305023314-538ac3df036e to 0.0.0-20260226085519-736f34afb267 | None |
| `github.com/canonical/lxd` | Go | From 0.0.0-20210305023314-538ac3df036e to 0.0.0-20260226085519-736f34afb267 | None |

Products: Canonical Lxd.

## How do I fix CVE-2026-34179?

Apply the vendor's patch.

## Is CVE-2026-34179 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34179 exists.

## Other vulnerabilities in Canonical lxd

- [CVE-2026-66897](https://insights.sbomify.com/CVE-2026-66897/): Instance template path traversal allows arbitrary host file write as root (critical 9.9)
- [CVE-2026-62420](https://insights.sbomify.com/CVE-2026-62420/): Cross-project cluster migration bypasses project restrictions via cluster notification flag (critical 9.9)
- [CVE-2026-63293](https://insights.sbomify.com/CVE-2026-63293/): Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root (critical 9.9)
- [CVE-2026-63294](https://insights.sbomify.com/CVE-2026-63294/): Root RCE via image backup.yaml symlink (critical 9.9)
- [CVE-2026-63296](https://insights.sbomify.com/CVE-2026-63296/): Project restriction bypass via instance migration config override (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34179 and fix it if it is affected.

What it is: CVE-2026-34179 is a critical vulnerability in Canonical lxd, published on 9 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34179 exists.

Affected packages and fixed versions:
- github.com/canonical/lxd (Go): affected all versions; no fix listed
- github.com/canonical/lxd (Go): affected from 0.0.0-20210305023314-538ac3df036e up to 0.0.0-20260226085519-736f34afb267; no fix listed
- github.com/canonical/lxd (Go): affected from 0.0.0-20210305023314-538ac3df036e up to 0.0.0-20260226085519-736f34afb267; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34179/ (Markdown: https://insights.sbomify.com/CVE-2026-34179/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34179
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34179
- OSV: https://osv.dev/vulnerability/CVE-2026-34179

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34179/
Summaries are generated and may contain mistakes; the official description above is the record.