CVE-2026-75528

Broken Link Checker <= 2.4.13 - Unauthenticated Stored Cross-Site Scripting via Comment Author URL / Link Log

2026-09-01 18:57
Adrien Brunner

Strategic Overview

Status
Patched in 2.4.13.1
Affected Plugin
Broken Link Checker
Affected Version
<= 2.4.13
CVSS
7.2High
Weakness type
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CVE
CVE-2026-75528
View all Broken Link Checker vulnerabilities

At a glance

CVE-2026-75528 is a high-severity Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in the Broken Link Checker WordPress plugin, affecting versions <= 2.4.13. It carries a CVSS score of 7.2 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 2.4.13.1; sites on affected versions should update now. Disclosed September 2026, reported by Adrien Brunner.

Vulnerability Overview

The Broken Link Checker plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Author URL / Link Log in all versions up to, and including, 2.4.13 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. Exploitation requires an administrator to perform the plugin's standard dismiss-and-recheck workflow on a link submitted by the attacker via the WordPress comment author URL field, after which the attacker's HTTP server issues a redirect to a URL containing an HTML/JavaScript payload that is stored verbatim in the link log.

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, and no interaction from a victim user.

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Reaching this weakness in Broken Link Checker <= 2.4.13 takes no account at all. Cross-site scripting happens when input from a request is written into a page without being escaped for the context it lands in, so the browser parses attacker-supplied text as markup or script.

Injected script runs with the privileges of whoever views the affected page, which is how these flaws turn into administrator session theft, silent account creation or persistent backdoors in page content. For Broken Link Checker the fix is 2.4.13.1: builds <= 2.4.13 are affected, anything from 2.4.13.1 onward is not.

Remediation

Update to version 2.4.13.1, 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: Broken Link Checker 2.4.13.1 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-2026-75528https://www.wordfence.com/threat-intel/vulnerabilities/id/ec96308f-3944-48c5-94be-b1555c0830b7https://nvd.nist.gov/vuln/detail/CVE-2026-75528

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C