Summary
A Helm contributor discovered an improper validation of type error when parsing Chart.yaml and index.yaml files that can lead to a panic.
Workarounds
Ensure YAML files are formatted as Helm expects prior to processing them with Helm.
References
Helm's security policy is spelled out in detail in our SECURITY document.
Credits
Disclosed by Jakub Ciolek at AlphaSense.
Impact
There are two areas of YAML validation that were impacted. First, when a Chart.yaml file had a null maintainer or the child or parent of a dependencies import-values could be parsed as something other than a string, helm lint would panic. Second, when an index.yaml had an empty entry in the list of chart versions Helm would panic on interactions with that repository.
CVE-2025-55198 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and user interaction required. 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 (3.18.5); 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
This issue has been resolved in Helm v3.18.5.
Frequently Asked Questions
- What is CVE-2025-55198? CVE-2025-55198 is a medium-severity security vulnerability in helm.sh/helm/v3 (go), affecting versions < 3.18.5. It is fixed in 3.18.5.
- How severe is CVE-2025-55198? CVE-2025-55198 has a CVSS score of 6.5 (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 helm.sh/helm/v3 are affected by CVE-2025-55198? helm.sh/helm/v3 (go) versions < 3.18.5 is affected.
- Is there a fix for CVE-2025-55198? Yes. CVE-2025-55198 is fixed in 3.18.5. Upgrade to this version or later.
- Is CVE-2025-55198 exploitable, and should I be worried? Whether CVE-2025-55198 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-2025-55198 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-2025-55198? Upgrade
helm.sh/helm/v3to 3.18.5 or later.