CVE-2025-55198: 
Helm vulnerability analysis and mitigation

Helm, a package manager for Charts for Kubernetes, disclosed a vulnerability (CVE-2025-55198) affecting versions prior to 3.18.5. The vulnerability was discovered by Jakub Ciolek at AlphaSense and publicly disclosed on August 13, 2025. The issue involves an improper validation of type error when parsing Chart.yaml and index.yaml files that can lead to a system panic (GitHub Advisory).

The vulnerability stems from two specific areas of YAML validation: First, when a Chart.yaml file contains a null maintainer or when the child or parent of a dependencies import-values could be parsed as something other than a string, causing helm lint to panic. Second, when an index.yaml has an empty entry in the list of chart versions, Helm would panic on interactions with that repository. The vulnerability has been assigned a CVSS v3.1 base score of 6.5 (Medium) with the vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H, indicating network accessibility with required user interaction (GitHub Advisory).

The vulnerability primarily affects the availability of the system. When exploited, it can cause the Helm application to panic, potentially disrupting operations that depend on Helm for package management. The CVSS metrics indicate no impact on confidentiality or integrity, but a high impact on availability (GitHub Advisory).

The vulnerability has been patched in Helm version 3.18.5. For users unable to immediately upgrade, a workaround involves ensuring YAML files are properly formatted according to Helm's expectations before processing them with Helm. This includes validating that maintainer entries are not null and that import-values fields contain proper string values (GitHub Advisory, GitHub Commit).