CVE-2026-28106

B2BKing Premium < 5.4.20 - Unauthenticated Open Redirect

2025-09-26 00:00

Strategic Overview

Status: Patched in 5.4.20
Affected Plugin: B2Bking
Affected Version: < 5.4.20
CVSS: 4.7Medium
Weakness type: CWE-601 · URL Redirection to Untrusted Site ('Open Redirect')
CVE: CVE-2026-28106

At a glance

CVE-2026-28106 is a medium-severity URL Redirection to Untrusted Site ('Open Redirect') vulnerability in the B2Bking WordPress plugin, affecting versions < 5.4.20. It carries a CVSS score of 4.7 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.4.20; sites on affected versions should update now. Disclosed September 2025, reported by 0xd4rk5id3.

Vulnerability Overview

The B2Bking plugin for WordPress is vulnerable to Open Redirect in all versions up to 5.4.20 (exclusive). This is due to insufficient validation on a redirect url.. This makes it possible for unauthenticated attackers to redirect users to potentially malicious sites if they can successfully trick them into performing an action.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site.

CWE-601: URL Redirection to Untrusted Site ('Open Redirect')

Reaching this weakness in B2Bking < 5.4.20 takes no account at all. An open redirect is a page that takes a destination from the request and sends the browser there without checking that the destination belongs to the site.

A link that starts on a trusted domain finishes on an attacker's, which is what makes phishing and consent-screen abuse credible to the person clicking it. For B2Bking the fix is 5.4.20: builds < 5.4.20 are affected, anything from 5.4.20 onward is not.

Remediation

Update to version 5.4.20, or a newer patched version

How does WordSec protect against this?

Requests carrying this pattern arrive without a session, so nothing upstream of the firewall gets a chance to reject them: WordSec's web application firewall inspects request payloads before WordPress loads them. None of that substitutes for the fix: B2Bking 5.4.20 closes this, and updating the plugin is the step that ends it.

Firewall
Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-28106 https://www.wordfence.com/threat-intel/vulnerabilities/id/69a6d8a5-0325-4436-8034-8353d2a68831 https://nvd.nist.gov/vuln/detail/CVE-2026-28106

CVSS Vector

4.7

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Base

Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeChanged
ConfidentialityNone
IntegrityLow
AvailabilityNone

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