TYPO3-EXT-SA-2026-030: Captcha Bypass in extension "Accessible Form Captcha" (bw_captcha)

• Release Date: October 20, 2026
• Component Type: Third party extension. This extension is not a part of the TYPO3 default installation.
• Component: "Accessible Form Captcha" (bw_captcha)
• Composer Package Name: blueways/bw-captcha
• Vulnerability Type: Captcha Bypass
• Affected Versions: 4.0.0 - 5.4.1
• Severity: Medium
• Suggested CVSS v4.0: AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
• References: CVE-2026-112067, CWE-804, CWE-656

Problem Description

The extension hides the correct answer to each CAPTCHA inside the image data of the CAPTCHA itself. Anyone who can request a CAPTCHA image can read the answer from it and submit it, so automated clients can pass the challenge.

This applies to the default configuration, because the audio feature that causes the answer to be embedded is enabled by default. Forms that rely on the CAPTCHA as their only protection against automated submissions are exposed to abuse by bots.

Solution

Updated version 5.4.2 is available from the TYPO3 extension manager, packagist and at

https://extensions.typo3.org/extension/download/bw_captcha/5.4.2/zip

Users of the extension are advised to update the extension as soon as possible.

Credits

Thanks to Sven Rothe for reporting the vulnerability, and to Maik Schneider for providing an updated version of the extension.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide.