● Medium · CVSS 6.4

How to Fix CVE-2026-32282: TOCTOU permits root escape on Linux via Root.Chmod in os in internal/syscall/unix

Q: Is CVE-2026-32282 being actively exploited?

Not at the time of writing. It is not listed in CISA's Known Exploited Vulnerabilities catalog. That status can change, so monitor the vendor advisory and the KEV catalog if the system is exposed.

Q: How severe is CVE-2026-32282?

CVSS rates it 6.4 (Medium). Use that score to set your patch priority alongside the other items in your queue.

Q: Do I have to take internal/syscall/unix offline to apply the patch?

It depends on the deployment. High-availability or clustered installs can usually patch one node at a time with no full outage. Standalone installs typically need a short restart. Always follow the vendor's documented upgrade steps.

Q: What if my vulnerability scanner still flags CVE-2026-32282 after I patch?

Re-run the scan after a service restart, then confirm the scanner's plugin set is up to date. Some scanners detect by banner version only and lag the official fix metadata by a release.

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

How to Fix CVE-2026-23272: Critical Vulnerability in Linux — Critical Vulnerability in Linux
How to Fix CVE-2026-23006: Critical Vulnerability in Linux — Critical Vulnerability in Linux
How to Fix CVE-2026-31751: comedi: dt2815: add hardware detection to prevent crash in Linux , comedi: dt2815: add hardware detection to prevent crash in Linux
How to Fix CVE-2026-1539: Critical Vulnerability in Red Hat Enterprise Linux 10 , Critical Vulnerability in Red Hat Enterprise Linux 10
How to Fix CVE-2026-3634: Improper Neutralization of CRLF Sequences ('CRLF Injection') , Improper Neutralization of CRLF Sequences ('CRLF Injection')

*By Sai Kiran Pandrala*

Last verified: 2026-05-25

⚡ At a glance


Severity	CVSS 6.4, Medium
Actively exploited?	No
Affected	Go Standard Library internal/syscall/unix (0 < 1.25.9, 1.26.0-0 < 1.26.2)
Fixed in	1.25.9, 1.26.2
Type (CWE)	CWE-61: UNIX Symbolic Link (Symlink) Following

CVE-2026-32282 is a toctou permits root escape on linux via root.chmod in os in internal/syscall/unix in Go Standard Library internal/syscall/unix. The fix is to upgrade to 1.25.9, 1.26.2 and apply the runnable commands below.

What is CVE-2026-32282?

On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.

In practical terms, a successful attacker gets compromise of the affected component as described in the vendor advisory. There is no confirmed in-the-wild exploitation listed in CISA's KEV catalog at the time of writing, but the CVSS rating still warrants prompt patching.

Am I affected?

You are affected if you run Go Standard Library internal/syscall/unix at a version listed in the Affected row above. Probe your installed build with the commands below.


# Confirm the installed version via your package manager
dpkg -l | grep -i internal/syscall/unix   # Debian/Ubuntu
rpm -qa | grep -i internal/syscall/unix   # RHEL/CentOS/Rocky

How to fix CVE-2026-32282

The primary fix is to upgrade to the patched build listed in the Fixed in row above (1.25.9, 1.26.2). Pick the platform that matches your install and run the commands below.

Linux (Ubuntu / Debian)


sudo apt-get update
sudo apt-get install --only-upgrade internal-syscall-unix
# Confirm the installed version meets or exceeds 1.25.9
dpkg -s internal-syscall-unix | grep ^Version

Linux (RHEL / CentOS / Rocky)


sudo dnf upgrade --security internal-syscall-unix -y
rpm -q internal-syscall-unix

Windows (PowerShell, admin)


winget upgrade --id 'GoStandardLibrary.internalsyscallunix' --silent --accept-source-agreements --accept-package-agreements
# If winget doesn't know the product, download the patched installer from the vendor and:
Start-Process -FilePath "$env:TEMP\internalsyscallunix-1.25.9.msi" -ArgumentList '/qn /norestart' -Wait

PowerShell script (Windows): detect, back up, upgrade, verify, log


# Run as Administrator
$ErrorActionPreference = 'Stop'
$log = "$env:ProgramData\internalsyscallunix-Patch-CVE-2026-32282.log"
function Write-Log($msg) { "$(Get-Date -Format s)  $msg" | Tee-Object -FilePath $log -Append }

Write-Log "Starting CVE-2026-32282 remediation for Go Standard Library internal/syscall/unix"

# 1. Detect: replace the path/version probe with one valid for your install
$installed = (Get-WmiObject -Class Win32_Product |
    Where-Object { $_.Name -like '*internal/syscall/unix*' } |
    Select-Object -First 1 -ExpandProperty Version)
Write-Log "Detected version: $installed"

if (-not $installed) {
    Write-Log "Product not installed on this host; nothing to do."
    return
}
if ([version]$installed -ge [version]'1.25.9') {
    Write-Log "Already at fixed version $installed; no action needed."
    return
}

# 2. Backup configuration to a timestamped folder
$backup = "$env:ProgramData\internalsyscallunix-Backup-$(Get-Date -Format yyyyMMdd-HHmm)"
New-Item -ItemType Directory -Path $backup -Force | Out-Null
$src = "$env:ProgramFiles\Go Standard Library\internal/syscall/unix"
if (Test-Path $src) { Copy-Item -Path $src -Destination $backup -Recurse -Force }
Write-Log "Backed up config to $backup"

# 3. Apply the patched installer
$installer = "$env:TEMP\internalsyscallunix-1.25.9.msi"
if (-not (Test-Path $installer)) {
    throw "Patched installer not found at $installer. Stage it from your software repo first."
}
Start-Process msiexec.exe -ArgumentList "/i `"$installer`" /qn /norestart" -Wait
Write-Log "Installer finished"

# 4. Verify
$verify = (Get-WmiObject -Class Win32_Product |
    Where-Object { $_.Name -like '*internal/syscall/unix*' } |
    Select-Object -First 1 -ExpandProperty Version)
if ([version]$verify -ge [version]'1.25.9') {
    Write-Log "SUCCESS: now at $verify (>= 1.25.9)"
} else {
    Write-Log "FAILURE: still at $verify after install"
    exit 1
}

Bash script (Linux): detect, back up, upgrade, verify, log


#!/usr/bin/env bash
set -euo pipefail
LOG=/var/log/internal-syscall-unix-patch-cve-2026-32282.log
log()  { echo "$(date -Iseconds)  $*" | tee -a "$LOG"; }

log "Starting CVE-2026-32282 remediation for Go Standard Library internal/syscall/unix"

# 1. Detect installed version (works for deb and rpm packages)
if command -v dpkg >/dev/null && dpkg -s internal-syscall-unix >/dev/null 2>&1; then
    CURRENT=$(dpkg-query -W -f='${Version}' internal-syscall-unix)
    PKG_MGR=apt
elif command -v rpm >/dev/null && rpm -q internal-syscall-unix >/dev/null 2>&1; then
    CURRENT=$(rpm -q --queryformat '%{VERSION}' internal-syscall-unix)
    PKG_MGR=dnf
else
    log "internal-syscall-unix not installed via apt or rpm; check your package manager or vendor instructions."
    exit 0
fi
log "Detected: internal-syscall-unix=$CURRENT (manager=$PKG_MGR)"

# 2. Backup config
BACKUP=/var/backups/internal-syscall-unix-$(date +%Y%m%d-%H%M)
mkdir -p "$BACKUP"
for d in /etc/internal-syscall-unix /etc/${pkg%%-*} ; do
    [ -d "$d" ] && cp -a "$d" "$BACKUP/" && log "Backed up $d to $BACKUP"
done

# 3. Upgrade
if [ "$PKG_MGR" = apt ]; then
    sudo apt-get update -y
    sudo apt-get install --only-upgrade -y internal-syscall-unix
else
    sudo dnf upgrade --security -y internal-syscall-unix
fi

# 4. Verify
if [ "$PKG_MGR" = apt ]; then
    NEW=$(dpkg-query -W -f='${Version}' internal-syscall-unix)
else
    NEW=$(rpm -q --queryformat '%{VERSION}' internal-syscall-unix)
fi
log "After upgrade: $NEW"
log "Done. Compare $NEW against 1.25.9 and restart the affected service if needed."

If you cannot patch immediately

These are runnable hardening commands. They reduce blast radius but they are not a replacement for the vendor patch.

No official vendor workaround is published for this CVE; patching is the documented fix. The runnable hardening below is generic defense in depth, not a substitute for the patch.

Restrict the affected service to trusted networks (Linux):


# Vendor advisory: https://go.dev/cl/763761
sudo iptables -A INPUT -p tcp --dport <port> -s 10.0.0.0/24 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport <port> -j DROP

Windows Firewall equivalent:


# Vendor advisory: https://go.dev/cl/763761
New-NetFirewallRule -DisplayName 'Allow affected service from admin subnet' -Direction Inbound -Action Allow -Protocol TCP -LocalPort <port> -RemoteAddress 10.0.0.0/24
New-NetFirewallRule -DisplayName 'Block affected service from everywhere else' -Direction Inbound -Action Block -Protocol TCP -LocalPort <port>

How to verify the fix worked

Run the version probe again and confirm the running build matches the Fixed in row above.


dpkg -l | grep -i "internal/syscall/unix"   # Debian/Ubuntu
rpm -qa | grep -i "internal/syscall/unix"   # RHEL/CentOS/Rocky

Expected output: the package version should meet or exceed 1.25.9.

Re-run any vulnerability scanner you used previously and confirm the finding for CVE-2026-32282 has cleared. Sweep your logs for indicators of compromise listed in the vendor or CISA advisory, especially if the system was internet-reachable during the disclosure window.

Frequently asked questions

Is CVE-2026-32282 being actively exploited?