# CVE-2026-4370: Juju has Improper TLS Client/Server authentication and certificate verification on Database Cluster

Source: https://junglewise.ai/threats/cve-2026-4370-juju-has-improper-tls-client-server-authentication-and-certificate  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-04-01  
License: CC BY 4.0 with a link back

CVE-2026-4370 · Severity: critical · CVSS 10 · Published 2026-04-01

A vulnerability was identified in Juju from version 3.2.0 until 3.6.19 and from version 4.0 until 4.0.4, where the internal Dqlite database cluster fails to perform proper TLS client and server authentication. Specifically, the Juju controller's database endpoint does not validate client certificates when a new node attempts to join the cluster. An unauthenticated attacker with network reachability to the Juju controller's Dqlite port can exploit this flaw to join the database cluster. Once joined, the attacker gains full read and write access to the underlying database, allowing for total data compromise.

Technologies: [Canonical Juju](https://junglewise.ai/threats/technologies/juju), [github.com/juju/juju (Go)](https://junglewise.ai/threats/technologies/github-com-juju-juju). Vendors: [Canonical](https://junglewise.ai/threats/vendors/canonical), [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2026-4370 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-4370 being exploited in the wild.

**How severe is CVE-2026-4370?** Critical severity, with a CVSS score of 10, published 1 April 2026.

**Which products and versions are affected?** github.com/juju/juju (Go) SEMVER:introduced=0, SEMVER:introduced=0,last_affected=0.0.0-20260401092550-1c1ac1922b57.

**Is there a fix for CVE-2026-4370?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**Am I affected by CVE-2026-4370?** Check whether you run Canonical Juju or github.com/juju/juju (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Canonical Juju
- github.com/juju/juju (Go) SEMVER:introduced=0, SEMVER:introduced=0,last_affected=0.0.0-20260401092550-1c1ac1922b57

## Identifiers

- CVE-2026-4370
- GHSA-gvrj-cjch-728p
- GO-2026-5405

## Related threats

- [Canonical Juju missing authorization in unit resources download](https://junglewise.ai/threats/cve-2026-93336-missing-authorization-in-the-unit-resources-download-route-in)
- [Canonical Juju race condition in API server userTokens map](https://junglewise.ai/threats/cve-2026-5774-canonical-juju-race-condition-in-api-server-usertokens-map)
- [Canonical Juju improper authorization in Controller facade](https://junglewise.ai/threats/cve-2026-5412-canonical-juju-improper-authorization-in-controller-facade)
- [Canonical Juju incorrect authorization in resource handler](https://junglewise.ai/threats/cve-2025-68153-canonical-juju-incorrect-authorization-in-resource-handler)
- [Canonical Juju Incorrect Authorization in Debug Log Endpoint](https://junglewise.ai/threats/cve-2025-68152-canonical-juju-incorrect-authorization-in-debug-log-endpoint)