CVE-2026-4370Public exploitNetwork attack vector

Unauthenticated database compromise via unchecked peer certificates

Published Apr 1, 2026 · Updated Apr 1, 2026

Improper authentication in Canonical Juju 3.2.0 through 3.6.19 and 4.0 through 4.0.4 allows remote attackers to read and write controller data. The controller's Dqlite endpoint on TCP port 17666 accepts cluster peers without validating client certificates, while its client skips server-certificate verification. Network reachability to that endpoint is sufficient to join the cluster without credentials, enabling database modification, privilege escalation, firewall changes, and service interruption.

CVSS severity10.0
Critical
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Canonical Juju 3.2.0 through 3.6.19 and 4.0 through 4.0.4 allows remote attackers to read and write controller data. The controller's Dqlite endpoint on TCP port 17666 accepts cluster peers without validating client certificates, while its client skips server-certificate verification. Network reachability to that endpoint is sufficient to join the cluster without credentials, enabling database modification, privilege escalation, firewall changes, and service interruption.

The record

CVE
CVE-2026-4370
Published
Apr 1, 2026
Updated
Apr 1, 2026
Vendor
Canonical
Product
Juju
Classifications
CWE-306, CWE-295, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=3.2.0 <3.6.20
  2. Affected versionversion=4.0 <4.0.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Canonical · Jujuversion=3.2.0 <3.6.20; version=4.0 <4.0.4

Published CVSS scores

10.0Canonical Ltd.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
CWE-295Improper Certificate Validation
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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