How to Fix CVE-2026-27653: Incorrect default permissions in Soliton SecureBrowser for OneGate

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

CVE-2026-27653 is a incorrect default permissions in Soliton Systems K.K. Soliton SecureBrowser for OneGate. The fix is to apply the vendor patch noted below.

What is CVE-2026-27653?

The installers for multiple products provided by Soliton Systems K.K. contain an issue with incorrect default permissions, which may allow arbitrary code to be executed with SYSTEM privileges. The CVSS base score is 6.7 (Medium). The official advisory is at https://www.soliton.co.jp/support/2026/006679.html.

Am I affected?

Check the version of Soliton SecureBrowser for OneGate you are running and compare it against the Affected row above (Soliton SecureBrowser for OneGate V1.0.0; Soliton SecureBrowser II V2.0.0 to V2.0.14; Soliton SecureWorkspace (formerly WrappingBox) V1.0.0 to V1.4.7). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:

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

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

How to fix CVE-2026-27653

Upgrade Soliton SecureBrowser for OneGate 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 soliton-securebrowser-for-onegate
dpkg -s soliton-securebrowser-for-onegate | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux

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

SUSE / openSUSE

sudo zypper refresh
sudo zypper update soliton-securebrowser-for-onegate
rpm -q soliton-securebrowser-for-onegate

Complete PowerShell remediation script (Windows)

# Fix script for CVE-2026-27653 affecting Soliton SecureBrowser for OneGate
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-27653-fix-$(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"
    $pkg = Get-Package -Name "*Soliton SecureBrowser for OneGate*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

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

    Write-Host "[3/4] Apply the upgrade to See vendor advisory"
    winget upgrade --name "Soliton SecureBrowser for OneGate" --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 "Soliton SecureBrowser for OneGate"
    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-2026-27653 affecting Soliton SecureBrowser for OneGate
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-27653-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 soliton-securebrowser-for-onegate 2>/dev/null | grep -i ^Version || echo "soliton-securebrowser-for-onegate not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q soliton-securebrowser-for-onegate || echo "soliton-securebrowser-for-onegate not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-27653-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/soliton-securebrowser-for-onegate /etc/soliton-securebrowser-for-onegate.d /etc/soliton-securebrowser-for-onegate.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 soliton-securebrowser-for-onegate
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y soliton-securebrowser-for-onegate
elif command -v yum >/dev/null; then
    yum update -y soliton-securebrowser-for-onegate
elif command -v zypper >/dev/null; then
    zypper --non-interactive update soliton-securebrowser-for-onegate
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s soliton-securebrowser-for-onegate 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q soliton-securebrowser-for-onegate
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-2026-27653" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-27653"

Disable the affected service (Linux)

sudo systemctl stop soliton-securebrowser-for-onegate 2>/dev/null || true
sudo systemctl disable soliton-securebrowser-for-onegate 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 soliton-securebrowser-for-onegate 2>/dev/null | grep -i ^Version
rpm -q soliton-securebrowser-for-onegate 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 "*Soliton SecureBrowser for OneGate*" | 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

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Is CVE-2026-27653 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-2026-27653?

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-2026-27653?

6.7 (Medium). Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H.

Where is the official advisory for CVE-2026-27653?

The vendor advisory is at https://www.soliton.co.jp/support/2026/006679.html. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-27653.

References

• Official vendor advisory: https://www.soliton.co.jp/support/2026/006679.html
• NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-27653
• CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• Additional reference: https://jvn.jp/en/jp/JVN41357120/

*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.*