How to Fix CVE-2026-35204: Path traversal in helm
By Sai Kiran Pandrala. Last verified: 2026-05-25.
| Severity | 8.4 (High) |
|---|---|
| Actively exploited? | No public listing in CISA KEV |
| Affected | helm >= 4.0.0, < 4.1.4 |
| Fixed in | helm 4.1.4 |
| Type (CWE) | CWE-22: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') |
What is CVE-2026-35204?
Helm is a package manager for Charts for Kubernetes. From 4.0.0 to 4.1.3, a specially crafted Helm plugin, when installed or updated, will cause Helm to write the contents of the plugin to an arbitrary filesystem location. To prevent this, validate that the plugin.yaml of the Helm plugin does not include a version: field containing POSIX dot-dot path separators ie. "/../".
Am I affected?
Run the version check that matches your platform:
# Linux
dpkg -s helm 2>/dev/null | grep -i version
rpm -q helm 2>/dev/null
helm --version 2>/dev/null
Compare what you see against the Affected row above (helm >= 4.0.0, < 4.1.4). If your build sits inside that range, you are exposed and should patch.
How to fix CVE-2026-35204
The primary fix is to upgrade helm to the patched build. Use the commands for your platform below; the patched version listed in the vendor advisory is: helm 4.1.4.
Ubuntu / Debian
sudo apt-get update
sudo apt-get install --only-upgrade helm
helm --version 2>/dev/null || dpkg -s helm | grep -i version
RHEL / CentOS / Rocky / AlmaLinux
sudo dnf upgrade --security helm -y
rpm -q helm
SUSE / openSUSE
sudo zypper patch --category security
rpm -q helm
Docker / Kubernetes
# Vendor advisory: https://github.com/helm/helm/security/advisories/GHSA-vmx8-mqv2-9gmg
# Pull the patched image
docker pull helm:latest
# Or pin to the patched tag from the vendor's registry
# Rolling update in Kubernetes
kubectl set image deployment/helm helm=helm:<patched-tag>
kubectl rollout status deployment/helm
Complete PowerShell remediation script (Windows)
# Fix script for CVE-2026-35204 affecting helm
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.
$ErrorActionPreference = "Stop"
$LogPath = "C:\Logs\CVE-2026-35204-fix-$(Get-Date -Format yyyyMMdd-HHmmss).log"
New-Item -ItemType Directory -Force (Split-Path $LogPath) | Out-Null
Start-Transcript -Path $LogPath -Append
try {
Write-Host "[1/4] Detecting installed version of helm"
$pkg = winget list --id "helm" 2>$null
Write-Host $pkg
Write-Host "[2/4] Backing up configuration"
$backup = "C:\Backup\helm-$(Get-Date -Format yyyyMMdd)"
New-Item -ItemType Directory -Force $backup | Out-Null
Get-ChildItem "C:\ProgramData\helm" -ErrorAction SilentlyContinue |
Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue
Write-Host "[3/4] Applying upgrade to helm 4.1.4"
winget upgrade --id "helm" --silent --accept-source-agreements --accept-package-agreements
# Fallback: Windows Update for OS-level fixes
if ($LASTEXITCODE -ne 0) {
Install-Module -Name PSWindowsUpdate -Force -SkipPublisherCheck -ErrorAction SilentlyContinue
Import-Module PSWindowsUpdate
Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
}
Write-Host "[4/4] Verifying patched build"
winget list --id "helm"
Write-Host "Fix applied. Reboot if prompted."
exit 0
} catch {
Write-Error "Patch failed: $_"
exit 1
} finally {
Stop-Transcript
}
Complete Bash remediation script (Linux)
#!/usr/bin/env bash
# Fix script for CVE-2026-35204 affecting helm
# Detect -> backup -> upgrade -> verify -> log.
set -euo pipefail
LOG="/var/log/cve-2026-35204-fix-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG") 2>&1
echo "[1/4] Detecting installed version"
if command -v dpkg >/dev/null; then
dpkg -s helm 2>/dev/null | grep -i version || echo "helm not installed via dpkg"
elif command -v rpm >/dev/null; then
rpm -q helm || echo "helm not installed via rpm"
fi
echo "[2/4] Backing up configuration"
BACKUP="/root/backup-cve-2026-35204-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/helm /etc/helm.d /etc/helm.conf; do
[ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done
echo "[3/4] Applying upgrade (target: helm 4.1.4)"
if command -v apt-get >/dev/null; then
apt-get update
apt-get install --only-upgrade -y helm
elif command -v dnf >/dev/null; then
dnf upgrade --security -y helm
elif command -v yum >/dev/null; then
yum update -y helm
elif command -v zypper >/dev/null; then
zypper --non-interactive patch --category security
fi
echo "[4/4] Verifying patched build"
if command -v dpkg >/dev/null; then
dpkg -s helm 2>/dev/null | grep -i version
elif command -v rpm >/dev/null; then
rpm -q helm
fi
echo "Done. Restart any running daemons that loaded the old library."
If you can't patch immediately
If you cannot apply the patched version today, restrict exposure with one of the following runnable controls. None replace the patch.
Network restriction (Linux, nftables)
# Block inbound traffic to the affected service from untrusted networks
sudo nft add table inet filter
sudo nft 'add chain inet filter input { type filter hook input priority 0 ; }'
sudo nft 'add rule inet filter input tcp dport {443, 80} ip saddr != 10.0.0.0/8 drop'
sudo nft list ruleset
Service-level fallback
# If the affected feature is optional, stop the service until the patch is applied
sudo systemctl stop helm
sudo systemctl disable helm
How to verify the fix worked
# Linux
helm --version 2>/dev/null || dpkg -s helm | grep -i version
rpm -q helm 2>/dev/null || true
# Windows
winget list | findstr /I "helm"
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5
Expected: the reported version is at or above helm 4.1.4. Restart any services that loaded the old library (systemctl restart <service> on Linux, restart the Windows service or reboot when prompted). For network appliances, run show version on the device and confirm the build matches the patched release.
Frequently asked questions
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Is CVE-2026-35204 actually being exploited?
According to the data sources above, no public confirmation of in-the-wild exploitation at this time. Either way, the fix is the same: apply the vendor patch.
Do I need to reboot after patching?
For OS or kernel updates, yes. For most userland packages a systemctl restart <service> is enough. Any process that loaded the old shared library keeps using it until restarted, so when in doubt, reboot.
What is the CVSS score?
8.4 (high). Refer to the vendor advisory for the exact vector string.
Where is the official advisory?
See the References section at the bottom of this page; the vendor's URL is the authoritative source for affected builds and patched versions.
References
- Official vendor advisory: https://github.com/helm/helm/security/advisories/GHSA-vmx8-mqv2-9gmg
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35204
- https://github.com/helm/helm/commit/36c8539e99bc42d7aef9b87d136254662d04f027
- https://github.com/helm/helm/releases/tag/v4.1.4
*Written by Sai Kiran Pandrala. Assembled from the official vendor advisory, NVD record, and CISA KEV listing on 2026-05-25. Always confirm against the vendor's advisory before applying changes in production.*