Summary
Juju: CloudSpec method leaking cloud credentials
Workarounds
The only mitigation is to restrict ingress to the controller API port 17070 on all controller machines (for vm deployments) or the controller service (for k8s deployments). The Juju CLI and other clients like libjuju or JAAS require ingress to port 17070 so any restricted access will need to take into account those access requirements.
Impact
If a user has login permission to a controller and knows the controller model UUID, they can call the CloudSpec method on the Controller facade and get cloud credentials used to bootstrap the controller.
The CloudSpec API is called by workers running in the controller to maintain connection to the cloud - this aspect is not the issue. The API is also called by the CLI when killing (force destroying a controller with juju kill-controller). This is the problematic aspect. The API is exposed to any client caller where that client has nothing more than logon permission on the controller. What should happen is that getting access to the credential should be limited to those client connections where the authenticated user has superuser or model admin permission.
This affect 2.9, 3.6, 4.0.6 (snap from 4.0/edge channel).
The fix will allow non-confidential, public information like cloud endpoint etc to be read, but only controller superusers or model admins will be able to see the credential details.
CVE-2026-5412 has a CVSS score of 9.9 (Critical). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.0.0-20260408003526-d395054dc2c3); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
No patch exists.
Frequently Asked Questions
- What is CVE-2026-5412? CVE-2026-5412 is a critical-severity security vulnerability in github.com/juju/juju (go), affecting versions < 0.0.0-20260408003526-d395054dc2c3. It is fixed in 0.0.0-20260408003526-d395054dc2c3.
- How severe is CVE-2026-5412? CVE-2026-5412 has a CVSS score of 9.9 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/juju/juju are affected by CVE-2026-5412? github.com/juju/juju (go) versions < 0.0.0-20260408003526-d395054dc2c3 is affected.
- Is there a fix for CVE-2026-5412? Yes. CVE-2026-5412 is fixed in 0.0.0-20260408003526-d395054dc2c3. Upgrade to this version or later.
- Is CVE-2026-5412 exploitable, and should I be worried? Whether CVE-2026-5412 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-5412 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-5412? Upgrade
github.com/juju/jujuto 0.0.0-20260408003526-d395054dc2c3 or later.