CVE-2025-71261

CVE-2025-71261 is a high-severity security vulnerability in github.com/harvester/harvester (go), affecting versions < 1.8.0. It is fixed in 1.8.0.

Summary

Workarounds

If developers can't upgrade to a fixed version, ensure that only authorized cluster administrators can access and modify the cluster-registration-url setting.

Resources

If there are any questions or comments about this advisory:

Impact

A vulnerability has been identified in the SUSE Virtualization (Harvester) Rancher integration mechanism where by default the registration client uses an insecure TLS option that fails to verify the remote server’s certificate. This security gap could allow the execution of a man-in-the-middle (MitM) attack against SUSE Virtualization.

An attacker with network-level access between the SUSE Virtualization and Rancher Manager could interfere with the TLS handshake and abuse it to bypass TLS as a security control. The registration client could be misled to send cluster registration requests to an impersonated remote service. Additionally, because the system processes response payloads without performing size validation, an attacker could induce a memory buffer overflow, leading to a potential crash of the SUSE Virtualization registration controller.

Note that this vulnerability only affects the cluster registration configuration (the cluster-registration-url setting) which is distinct from the secured configuration used to maintain operational connectivity between SUSE Virtualization and Rancher Manager, as well as between the manager and hosted downstream clusters.

Please consult the associated MITRE ATT&CK - Technique - Adversary-in-the-Middle and MITRE ATT&CK - Technique - Endpoint Denial of Service: Application or System Exploitation for further information about this category of attack.

CVE-2025-71261 has a CVSS score of 8.6 (High). 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 (1.8.0); upgrading removes the vulnerable code path.

Affected versions

github.com/harvester/harvester (< 1.8.0)

Security releases

github.com/harvester/harvester → 1.8.0 (go)

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.

See it in your environment

Remediation advice

This vulnerability is addressed by updating the registration client’s default behaviour to validate the certificate presented by the remote server against the list of trusted system root certificate authority (CA) and those defined by the additional-ca setting.

Patched versions of SUSE Virtualization include releases v1.8.0 or newer.

Frequently Asked Questions

  1. What is CVE-2025-71261? CVE-2025-71261 is a high-severity security vulnerability in github.com/harvester/harvester (go), affecting versions < 1.8.0. It is fixed in 1.8.0.
  2. How severe is CVE-2025-71261? CVE-2025-71261 has a CVSS score of 8.6 (High). 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.
  3. Which versions of github.com/harvester/harvester are affected by CVE-2025-71261? github.com/harvester/harvester (go) versions < 1.8.0 is affected.
  4. Is there a fix for CVE-2025-71261? Yes. CVE-2025-71261 is fixed in 1.8.0. Upgrade to this version or later.
  5. Is CVE-2025-71261 exploitable, and should I be worried? Whether CVE-2025-71261 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
  6. What actually determines whether CVE-2025-71261 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.
  7. How do I fix CVE-2025-71261? Upgrade github.com/harvester/harvester to 1.8.0 or later.

Other vulnerabilities in github.com/harvester/harvester

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