Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion
Helm is a package manager for Charts for Kubernetes. Prior to version 3.18.5, it is possible to craft a JSON Schema file in a manner which could cause Helm to use all available memory and have an out of memory (OOM) termination. This issue has been resolved in Helm 3.18.5. A workaround involves ensuring all Helm charts that are being loaded into Helm do not have any reference of $ref pointing to /dev/zero.
02 / AFFECTED SOFTWARE
Affected packages
37 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
Helm is a package manager for Charts for Kubernetes. Prior to version 3.18.5, it is possible to craft a JSON Schema file in a manner which could cause Helm to use all available memory and have an out of memory (OOM) termination. This issue has been resolved in Helm 3.18.5. A workaround involves ensuring all Helm charts that are being loaded into Helm do not have any reference of $ref pointing to /dev/zero.
Helm Charts with Specific JSON Schema Values Can Cause Memory Exhaustion in helm.sh/helm
A Helm contributor discovered that it was possible to craft a JSON Schema file in a manner which could cause Helm to use all available memory and have an out of memory (OOM) termination. ### Impact A malicious chart can point `$ref` in _values.schema.json_ to a device (e.g. `/dev/*`) or other problem file which could cause Helm to use all available memory and have an out of memory (OOM) termination. ### Patches This issue has been resolved in Helm v3.18.5. ### Workarounds Make sure that all Helm charts that are being loaded into Helm doesn't have any reference of `$ref` pointing to `/dev/zero`. ### References Helm's security policy is spelled out in detail in our [SECURITY](https://github.com/helm/community/blob/master/SECURITY.md) document. ### Credits Disclosed by Jakub Ciolek at AlphaSense.
Helm is a package manager for Charts for Kubernetes. Prior to version 3.18.5, it is possible to craft a JSON Schema file in a manner which could cause Helm to use all available memory and have an out of memory (OOM) termination. This issue has been resolved in Helm 3.18.5. A workaround involves ensuring all Helm charts that are being loaded into Helm do not have any reference of $ref pointing to /dev/zero.
05 / REFERENCES
Further evidence
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/55xxx/CVE-2025-55199.json
- https://github.com/helm/helm/commit/b78692c18f0fb38fe5ba4571a674de067a4c53a5
- https://github.com/helm/helm/security/advisories/GHSA-9h84-qmv7-982p
- https://nvd.nist.gov/vuln/detail/CVE-2025-55199
- https://github.com/helm/helm