⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● Critical · CVSS 9.5

How to Fix CVE-2026-27493: Code injection in n8n

By Sai Kiran Pandrala. Last verified: 2026-05-25.

CVE-2026-27493 is a code injection in n8n-io n8n. The fix is to apply the vendor patch noted below.

⚡ At a glance
Severity9.5 (Critical)
Actively exploited?No public listing in CISA KEV
Affectedn8n < 1.123.22; n8n >= 2.0.0, < 2.9.3; n8n >= 2.10.0, < 2.10.1
Fixed inSee vendor advisory
Type (CWE)CWE-94: Improper Control of Generation of Code ('Code Injection')

What is CVE-2026-27493?

n8n is an open source workflow automation platform. Prior to versions 2.10.1, 2.9.3, and 1.123.22, a second-order expression injection vulnerability existed in n8n's Form nodes that could allow an unauthenticated attacker to inject and evaluate arbitrary n8n expressions by submitting crafted form data. When chained with an expression sandbox escape, this could escalate to remote code execution on the n8n host. The vulnerability requires a specific workflow configuration to be exploitable. First, a form node with a field interpolating a value provided by an unauthenticated user, e.g. a form submitted value. Second, the field value must begin with an = character, which caused n8n to treat it as an expression and triggered a double-evaluation of the field content. There is no practical reason for a workflow designer to prefix a field with = intentionally — the character is not rendered in the output, so the result would not match the designer's expectations. If added accidentally, it would be noticeable and very unlikely to persist. An unauthenticated attacker would need to either know about this specific circumstance on a target instance or discover a matching form by chance. Even when the preconditions are met, the expression injection alone is limited to data accessible within the n8n expression context. Escalation to remote code execution requires chaining with a separate sandbox escape vulnerability. The issue has been fixed in n8n versions 2.10.1, 2.9.3, and 1.123.22. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations. Review usage of form nodes manually for above mentioned preconditions, disable the Form node by adding n8n-nodes-base.form to the NODES_EXCLUDE environment variable, and/or disable the Form Trigger node by adding n8n-nodes-base.formTrigger to the NODES_EXCLUDE environment variable. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures. The CVSS base score is 9.5 (Critical), which puts this in the upper risk band and warrants a fast patch cycle. The official advisory is at https://github.com/n8n-io/n8n/security/advisories/GHSA-75g8-rv7v-32f7.

Am I affected?

Check the version of n8n you are running and compare it against the Affected row above (n8n < 1.123.22; n8n >= 2.0.0, < 2.9.3; n8n >= 2.10.0, < 2.10.1). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


# Linux package check
dpkg -s n8n 2>/dev/null | grep -i ^Version
rpm -q n8n 2>/dev/null
command -v n8n >/dev/null && n8n --version 2>/dev/null


# Windows (PowerShell)
Get-Package -Name "*n8n*" -ErrorAction SilentlyContinue | Select-Object Name, Version
winget list --name "n8n" 2>$null

How to fix CVE-2026-27493

Upgrade n8n to a patched build: See vendor advisory. The vendor advisory is the source of truth for the exact fixed version.

Ubuntu / Debian


sudo apt-get update
sudo apt-get install --only-upgrade n8n
dpkg -s n8n | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


sudo dnf upgrade --refresh n8n -y
# or for older releases:
sudo yum update n8n -y
rpm -q n8n

SUSE / openSUSE


sudo zypper refresh
sudo zypper update n8n
rpm -q n8n

Node.js / npm


# Update the affected package in your project
npm install n8n@latest
npm ls n8n
npm audit fix

Complete PowerShell remediation script (Windows)


# Fix script for CVE-2026-27493 affecting n8n
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-27493-fix-$(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] Detect installed version"
    $pkg = Get-Package -Name "*n8n*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

    Write-Host "[2/4] Backup configuration"
    $backup = "C:\Backup\n8n-$(Get-Date -Format yyyyMMdd)"
    New-Item -ItemType Directory -Force $backup | Out-Null
    Get-ChildItem "C:\ProgramData\n8n" -ErrorAction SilentlyContinue |
        Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "n8n" --silent --accept-source-agreements --accept-package-agreements
    if ($LASTEXITCODE -ne 0) {
        # Fallback: pull latest via OS update channel
        Install-Module -Name PSWindowsUpdate -Force -SkipPublisherCheck -ErrorAction SilentlyContinue
        Import-Module PSWindowsUpdate
        Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
    }

    Write-Host "[4/4] Verify the patched build"
    winget list --name "n8n"
    Write-Host "Patch 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-2026-27493 affecting n8n
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-27493-fix-$(date +%Y%m%d-%H%M%S).log"
exec > >(tee -a "$LOG") 2>&1

echo "[1/4] Detect installed version"
if command -v dpkg >/dev/null; then
    dpkg -s n8n 2>/dev/null | grep -i ^Version || echo "n8n not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q n8n || echo "n8n not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-27493-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/n8n /etc/n8n.d /etc/n8n.conf; do
    [ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done

echo "[3/4] Apply the upgrade (target: See vendor advisory)"
if command -v apt-get >/dev/null; then
    apt-get update
    apt-get install --only-upgrade -y n8n
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y n8n
elif command -v yum >/dev/null; then
    yum update -y n8n
elif command -v zypper >/dev/null; then
    zypper --non-interactive update n8n
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s n8n 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q n8n
fi
echo "Done. Restart any service that loaded the old library."

If you can't patch immediately

Apply at least one of the following inline controls until you can deploy the patched build. None replace the upgrade.

Restrict exposure with nftables (Linux)


# Allow only trusted CIDR to reach the affected service ports
sudo nft add table inet filter 2>/dev/null || true
sudo nft 'add chain inet filter input { type filter hook input priority 0 ; }' 2>/dev/null || true
sudo nft 'add rule inet filter input tcp dport {80, 443} ip saddr != 10.0.0.0/8 drop'
sudo nft list ruleset

Block at the host firewall (Windows)


New-NetFirewallRule -DisplayName "Block-CVE-2026-27493" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-27493"

Disable the affected service (Linux)


sudo systemctl stop n8n 2>/dev/null || true
sudo systemctl disable n8n 2>/dev/null || true

If the vendor advisory lists an official workaround, prefer that wording verbatim. If no workaround is published, the only safe remediation is the patch.

How to verify the fix worked

After upgrading, confirm the installed version matches the patched build and that no old library is still loaded by a long-running process.


# Linux
dpkg -s n8n 2>/dev/null | grep -i ^Version
rpm -q n8n 2>/dev/null || true
# Pid map check for old library handles
sudo lsof +c0 2>/dev/null | grep -i "DEL.*lib" || true


# Windows
Get-Package -Name "*n8n*" | Select-Object Name, Version
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected: the reported version is at or above See vendor advisory. Restart the affected service (systemctl restart <service> on Linux, or restart the Windows service) so it loads the patched binary.

Frequently asked questions

Other vulnerabilities in the same area that are worth patching alongside this one:

Is CVE-2026-27493 actively exploited?

There is no public confirmation of exploitation in the wild listed in CISA KEV at the time of this writing. Patch anyway. Public exploits commonly follow disclosure within weeks.

Do I need to reboot after patching CVE-2026-27493?

For kernel and OS-level updates, yes. For most userland packages a systemctl restart <service> is enough on Linux, and restarting the Windows service or app on Windows. Any process that loaded the old library keeps using it until restarted.

What is the CVSS score for CVE-2026-27493?

9.5 (Critical). Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H.

Where is the official advisory for CVE-2026-27493?

The vendor advisory is at https://github.com/n8n-io/n8n/security/advisories/GHSA-75g8-rv7v-32f7. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-27493.

References

*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.*