● Medium · CVSS 4.7

How to Fix CVE-2026-28106: Open redirect in B2BKing Premium

Q: What is the CVSS score for CVE-2026-28106?

4.7 (Medium). Vector: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N`.

Q: Where is the official advisory for CVE-2026-28106?

The vendor advisory is at [https://patchstack.com/database/wordpress/plugin/b2bking/vulnerability/wordpress-b2bking-premium-plugin-5-3-80-open-redirection-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/b2bking/vulnerability/wordpress-b2bking-premium-plugin-5-3-80-open-redirection-vulnerability?_s_id=cve). The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-28106.

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

CVE-2026-28106 is a open redirect in Kings Plugins B2BKing Premium. The fix is to upgrade to B2BKing Premium 5.4.20.

⚡ At a glance


Severity	4.7 (Medium)
Actively exploited?	No public listing in CISA KEV
Affected	B2BKing Premium n/a to <5.4.20
Fixed in	B2BKing Premium 5.4.20
Type (CWE)	CWE-601 URL Redirection to Untrusted Site ('Open Redirect')

What is CVE-2026-28106?

URL Redirection to Untrusted Site ('Open Redirect') vulnerability in Kings Plugins B2BKing Premium allows Phishing.This issue affects B2BKing Premium: from n/a before 5.4.20. The CVSS base score is 4.7 (Medium). The official advisory is at https://patchstack.com/database/wordpress/plugin/b2bking/vulnerability/wordpress-b2bking-premium-plugin-5-3-80-open-redirection-vulnerability?_s_id=cve.

Am I affected?

Check the version of B2BKing Premium you are running and compare it against the Affected row above (B2BKing Premium n/a to <5.4.20). If your build sits inside the affected range, you must patch.

Run the version check that fits your platform:


# Linux package check
dpkg -s b2bking-premium 2>/dev/null | grep -i ^Version
rpm -q b2bking-premium 2>/dev/null
command -v b2bking-premium >/dev/null && b2bking-premium --version 2>/dev/null


# Windows (PowerShell)
Get-Package -Name "*B2BKing Premium*" -ErrorAction SilentlyContinue | Select-Object Name, Version
winget list --name "B2BKing Premium" 2>$null

How to fix CVE-2026-28106

Upgrade B2BKing Premium to a patched build: B2BKing Premium 5.4.20. 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 b2bking-premium
dpkg -s b2bking-premium | grep -i ^Version

RHEL / CentOS / Rocky / AlmaLinux


sudo dnf upgrade --refresh b2bking-premium -y
# or for older releases:
sudo yum update b2bking-premium -y
rpm -q b2bking-premium

SUSE / openSUSE


sudo zypper refresh
sudo zypper update b2bking-premium
rpm -q b2bking-premium

Node.js / npm


# Update the affected package in your project
npm install B2BKing Premium@latest
npm ls B2BKing Premium
npm audit fix

Complete PowerShell remediation script (Windows)


# Fix script for CVE-2026-28106 affecting B2BKing Premium
# Run as administrator. Detect -> backup -> upgrade -> verify -> log.

$ErrorActionPreference = "Stop"
$LogPath  = "C:\Logs\CVE-2026-28106-fix-$(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"
    $pkg = Get-Package -Name "*B2BKing Premium*" -ErrorAction SilentlyContinue
    if ($pkg) { $pkg | Format-Table Name, Version }
    else { Write-Host "Not detected via Get-Package; try winget list" }

    Write-Host "[2/4] Backup configuration"
    $backup = "C:\Backup\b2bking-premium-$(Get-Date -Format yyyyMMdd)"
    New-Item -ItemType Directory -Force $backup | Out-Null
    Get-ChildItem "C:\ProgramData\B2BKing Premium" -ErrorAction SilentlyContinue |
        Copy-Item -Destination $backup -Recurse -Force -ErrorAction SilentlyContinue

    Write-Host "[3/4] Apply the upgrade to B2BKing Premium 5.4.20"
    winget upgrade --name "B2BKing Premium" --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 "B2BKing Premium"
    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-2026-28106 affecting B2BKing Premium
# Detect -> backup -> upgrade -> verify -> log.

set -euo pipefail
LOG="/var/log/cve-2026-28106-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 b2bking-premium 2>/dev/null | grep -i ^Version || echo "b2bking-premium not installed via dpkg"
elif command -v rpm >/dev/null; then
    rpm -q b2bking-premium || echo "b2bking-premium not installed via rpm"
fi

echo "[2/4] Backup configuration"
BACKUP="/root/backup-cve-2026-28106-$(date +%Y%m%d)"
mkdir -p "$BACKUP"
for d in /etc/b2bking-premium /etc/b2bking-premium.d /etc/b2bking-premium.conf; do
    [ -e "$d" ] && cp -a "$d" "$BACKUP/" || true
done

echo "[3/4] Apply the upgrade (target: B2BKing Premium 5.4.20)"
if command -v apt-get >/dev/null; then
    apt-get update
    apt-get install --only-upgrade -y b2bking-premium
elif command -v dnf >/dev/null; then
    dnf upgrade --refresh -y b2bking-premium
elif command -v yum >/dev/null; then
    yum update -y b2bking-premium
elif command -v zypper >/dev/null; then
    zypper --non-interactive update b2bking-premium
fi

echo "[4/4] Verify the patched build"
if command -v dpkg >/dev/null; then
    dpkg -s b2bking-premium 2>/dev/null | grep -i ^Version
elif command -v rpm >/dev/null; then
    rpm -q b2bking-premium
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-2026-28106" -Direction Inbound -Action Block -Protocol TCP -LocalPort 80,443 -RemoteAddress Any -Enabled True
Get-NetFirewallRule -DisplayName "Block-CVE-2026-28106"

Disable the affected service (Linux)


sudo systemctl stop b2bking-premium 2>/dev/null || true
sudo systemctl disable b2bking-premium 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 b2bking-premium 2>/dev/null | grep -i ^Version
rpm -q b2bking-premium 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 "*B2BKing Premium*" | Select-Object Name, Version
Get-HotFix | Sort-Object InstalledOn -Descending | Select-Object -First 5

Expected: the reported version is at or above B2BKing Premium 5.4.20. 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:

How to Fix CVE-2026-7419: Buffer Overflow in HiPER 1250GW — Buffer Overflow in HiPER 1250GW
How to Fix CVE-2026-34155: RAUC: Improper Signing of Plain Bundles Exceeding 2 GiB in rauc — RAUC: Improper Signing of Plain Bundles Exceeding 2 GiB in rauc
How to Fix CVE-2026-7085: Path Traversal in Toonflow-app , Path Traversal in Toonflow-app
How to Fix CVE-2026-22626: Critical Vulnerability in HS-AFS-S1H1 , Critical Vulnerability in HS-AFS-S1H1
How to Fix CVE-2026-27153: Incorrect authorization in discourse , Incorrect authorization in discourse

Is CVE-2026-28106 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-2026-28106?

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-2026-28106?

4.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N.

Where is the official advisory for CVE-2026-28106?

The vendor advisory is at https://patchstack.com/database/wordpress/plugin/b2bking/vulnerability/wordpress-b2bking-premium-plugin-5-3-80-open-redirection-vulnerability?_s_id=cve. The NVD record is at https://nvd.nist.gov/vuln/detail/CVE-2026-28106.

References

Official vendor advisory: https://patchstack.com/database/wordpress/plugin/b2bking/vulnerability/wordpress-b2bking-premium-plugin-5-3-80-open-redirection-vulnerability?_s_id=cve
NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28106
CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

*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.*