# CVE-2026-62420: Cross-project cluster migration bypasses project restrictions via cluster notification flag

> Authenticated attackers can bypass project restrictions during cross-project instance migrations in LXD, introducing disallowed configurations into restricted projects.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 12 Aug 2026
- **Updated:** 12 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-62420, GHSA-v9wr-9r7q-fh4g, UBUNTU-CVE-2026-62420

## What is CVE-2026-62420?

CVE-2026-62420 is a critical missing authorization vulnerability in Canonical LXD, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

An authorization bypass vulnerability in LXD allows an authenticated attacker to bypass target project security restrictions during cross-project instance migrations. When moving an instance cross-project to a different cluster member via POST /1.0/instances/{name} with migration: true, project: <target>, and target: <member>, the destination node skips all project restriction checks because the request arrives as an internal cluster notification. An attacker can exploit this to introduce disallowed instance configurations into a restricted project.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-62420?

It affects 1 product.


Products: Canonical Lxd.

## How do I fix CVE-2026-62420?

Apply the vendor's patch.

## Is CVE-2026-62420 being exploited?

There is no known exploitation of CVE-2026-62420 in the wild and no public exploit code.

## 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-2026-63293](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)
- [CVE-2026-63297](https://insights.sbomify.com/CVE-2026-63297/): Cross-project instance copy bypasses target project restrictions via TOCTOU in config merge (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-62420 and fix it if it is affected.

What it is: CVE-2026-62420 is a critical missing authorization vulnerability in Canonical LXD, published on 12 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-62420 in the wild and no public exploit code.

Affected product: Canonical LXD. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-62420/ (Markdown: https://insights.sbomify.com/CVE-2026-62420/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-62420
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62420
- OSV: https://osv.dev/vulnerability/CVE-2026-62420

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-62420/
Summaries are generated and may contain mistakes; the official description above is the record.