Canonical Juju up to 3.6.19/4.0.3 certificate validation

Summaryinfo

A vulnerability identified as critical has been detected in Canonical Juju up to 3.6.19/4.0.3. This affects an unknown function. Performing a manipulation results in certificate validation. This vulnerability is known as CVE-2026-4370. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Canonical Juju up to 3.6.19/4.0.3. It has been classified as critical. This affects some unknown functionality. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was published by Harry Pidcock. It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-4370 since 03/18/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

Upgrading to version 3.6.20 or 4.0.4 eliminates this vulnerability.

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Productinfo

Vendor

• Canonical

Name

• Juju

Version

• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4
• 3.6.5
• 3.6.6
• 3.6.7
• 3.6.8
• 3.6.9
• 3.6.10
• 3.6.11
• 3.6.12
• 3.6.13
• 3.6.14
• 3.6.15
• 3.6.16
• 3.6.17
• 3.6.18
• 3.6.19
• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3

License

• open-source

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CPE 2.2info

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