# CVE-2024-6156: lxd CA certificate sign check bypass

> Attackers can bypass LXD PKI authentication if their certificate is in the trust store, allowing unauthorized access to the container management service.

- **Severity:** Low 3.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 5 Dec 2024
- **Updated:** 18 Mar 2025
- **Also known as:** DEBIAN-CVE-2024-6156, GHSA-4c49-9fpc-hc3v, GO-2024-3312, UBUNTU-CVE-2024-6156

## What is CVE-2024-6156?

CVE-2024-6156 is a low-severity authentication bypass vulnerability in Canonical Ltd. LXD, published on 5 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Mark Laing discovered that LXD's PKI mode, until version 5.21.2, could be bypassed if the client's certificate was present in the trust store.

Weakness: CWE-295 (Improper Certificate Validation)

## Which versions are affected by CVE-2024-6156?

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 | 0.0.0-20240708073652-5a492a3f0036 |
| `github.com/canonical/lxd` | Go | All versions | 0.0.0-20240708073652-5a492a3f0036 |
| `github.com/canonical/lxd` | Go | All versions | 0.0.0-20240708073652-5a492a3f0036 |

Products: Canonical Lxd.

## How do I fix CVE-2024-6156?

Upgrade github.com/canonical/lxd to 0.0.0-20240708073652-5a492a3f0036 or later.

## Is CVE-2024-6156 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-6156 exists.

## Other vulnerabilities in Canonical Ltd. 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-2024-6156 and fix it if it is affected.

What it is: CVE-2024-6156 is a low-severity authentication bypass vulnerability in Canonical Ltd. LXD, published on 5 Dec 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-6156 exists.

Affected packages and fixed versions:
- github.com/canonical/lxd (Go): affected all versions; fixed in 0.0.0-20240708073652-5a492a3f0036
- github.com/canonical/lxd (Go): affected all versions; fixed in 0.0.0-20240708073652-5a492a3f0036
- github.com/canonical/lxd (Go): affected all versions; fixed in 0.0.0-20240708073652-5a492a3f0036

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-2024-6156/ (Markdown: https://insights.sbomify.com/CVE-2024-6156/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-6156
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-6156
- OSV: https://osv.dev/vulnerability/CVE-2024-6156

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-6156/
Summaries are generated and may contain mistakes; the official description above is the record.