Summary
Rancher's SAML-based login via CLI can be denied by unauthenticated users
Workarounds
Users can refrain from using the Rancher CLI to log in as a workaround. Otherwise, users are advised to upgrade to a patched version of Rancher Manager.
References
If you have any questions or comments about this advisory:
- Reach out to the SUSE Rancher Security team for security related inquiries.
- Open an issue in the Rancher repository.
- Verify with our support matrix and product support lifecycle.
Impact
A vulnerability has been identified within Rancher where it is possible for an unauthenticated user to list all CLI authentication tokens and delete them before the CLI is able to get the token value. This effectively prevents users from logging in via the CLI when using rancher token as the execution command (instead of the token directly being in the kubeconfig).
Note that this token is not the kubeconfig token and if an attacker is able to intercept it they can't use it to impersonate a real user since it is encrypted.
This happens because for SAML-based authentication providers, the login flow from the CLI works by generating a link to be pasted in the browser, and then polling every 10 seconds for the /v3-public/authTokens/<token name> endpoint. The <token name> is randomly generated by the CLI. Once the login flow succeeds, Rancher creates an auth token (with an encrypted token value). The CLI then deletes the authToken.
Rancher deployments using only the local authentication provider, or non-SAML-based authentication providers, are not impacted by this vulnerability. SAML-based users not using the CLI are also not impacted.
Please consult the associated MITRE ATT&CK - Technique - Account Access Removal for further information about this category of attack.
CVE-2025-23387 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no 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 (2.8.13, 2.9.7, 2.10.3); 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.
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The fix involves removing GET and DELETE methods for the authTokens collection.
Patched versions include releases v2.8.13, v2.9.7 and v2.10.3.
Frequently Asked Questions
- What is CVE-2025-23387? CVE-2025-23387 is a medium-severity security vulnerability in github.com/rancher/rancher (go), affecting versions >= 2.8.0, < 2.8.13. It is fixed in 2.8.13, 2.9.7, 2.10.3.
- How severe is CVE-2025-23387? CVE-2025-23387 has a CVSS score of 5.3 (Medium). 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/rancher/rancher are affected by CVE-2025-23387? github.com/rancher/rancher (go) versions >= 2.8.0, < 2.8.13 is affected.
- Is there a fix for CVE-2025-23387? Yes. CVE-2025-23387 is fixed in 2.8.13, 2.9.7, 2.10.3. Upgrade to this version or later.
- Is CVE-2025-23387 exploitable, and should I be worried? Whether CVE-2025-23387 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-2025-23387 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-2025-23387?
- Upgrade
github.com/rancher/rancherto 2.8.13 or later - Upgrade
github.com/rancher/rancherto 2.9.7 or later - Upgrade
github.com/rancher/rancherto 2.10.3 or later
- Upgrade