---
id: CVE-2026-63308
title: Helm Files.Lines Denial of Service via Empty Chart Files
summary: >-
  Helm through 4.2.3, fixed in commit ba6c9a2, contains a denial of service
  vulnerability in the Files.Lines template helper in pkg/engine/files.go that
  allows attackers to trigger an index out of range panic by including
  zero-length byte …
severity: medium
cvss: 4.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L'
cvssSource: cna
cwe:
  - CWE-129
vendor: helm
product: helm
affected:
  - helm <= 4.2.3
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-07-17T17:25:36.932375Z'
exploitAvailable: true
published: '2026-07-17'
updated: '2026-10-29'
sourceUpdated: '2026-10-29T21:16:18.580Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-63308'
references:
  - url: 'https://github.com/helm/helm/issues/32279'
    label: Researcher Disclosure
  - url: 'https://github.com/helm/helm/pull/32290'
    label: Pull Request
  - url: >-
      https://github.com/helm/helm/commit/ba6c9a29efa7bf9198dad6a5ec12b4fb30c96017
    label: Patch Commit
  - url: >-
      https://www.vulncheck.com/advisories/helm-files-lines-denial-of-service-via-empty-chart-files
    label: >-
      VulnCheck Advisory: Helm Files.Lines Denial of Service via Empty Chart
      Files
tags:
  - cve.org
  - exploit-available
epss: 0.00486
epssPercentile: 0.41857
ingestedAt: '2026-11-03T08:39:35.578Z'
---

## Overview

Helm through 4.2.3, fixed in commit ba6c9a2, contains a denial of service vulnerability in the Files.Lines template helper in pkg/engine/files.go that allows attackers to trigger an index out of range panic by including zero-length byte slices in chart files. Attackers can include empty files in Helm charts to cause deterministic render failures across template, install, upgrade, lint, and SDK Engine.Render operations.

## Affected

- `helm <= 4.2.3`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.