# Broken Link Checker <= 2.4.14.1 - Unauthenticated Authentication Bypass to Scan Report Recipient Removal

- **ID:** WPSEC-2026-0923
- **Plugin:** Broken Link Checker (`broken-link-checker`), https://wordpress.org/plugins/broken-link-checker/
- **Affected versions:** all versions before 2.4.15
- **Fixed in:** 2.4.15 (Update to 2.4.15 or later.)
- **Severity:** Medium 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N)
- **Weakness:** CWE-287
- **Usage among sites WPSec scans:** plugin Low, affected versions Low (as of 2026-10-14)
- **Attack surface analysis:** https://attacksurface.wpsec.com/plugin/broken-link-checker
- **Fix released:** 2026-10-12
- **Published:** 2026-10-14
- **URL:** https://wpsec.com/vuln/WPSEC-2026-0923/

## Description

The Broken Link Checker plugin for WordPress is vulnerable to Authentication Bypass via the recipient activation webhook in all versions up to, and including, 2.4.14.1, due to the get_recipient_by_key() function matching registered-user recipients on the MD5 hash of their email address alone, without checking the stored random recipient key. This makes it possible for unauthenticated attackers who know a registered recipient's email address to forge a cancellation token and remove that user from the scan report recipients.

## References

- https://wpsec.com/vuln/WPSEC-2026-0923/
- https://plugins.svn.wordpress.org/broken-link-checker/tags/2.4.15/
- https://wordpress.org/plugins/broken-link-checker/

Source: WPSec, https://wpsec.com/vuln/WPSEC-2026-0923/

License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Free to use, share and adapt, also commercially, if you credit WPSec and link to this advisory.