CVE-2026-40935: WWBN/AVideo has CAPTCHA Bypass via Attacker-Controlled Length Parameter and Missing Token Invalidation on Failure

Published Apr 21, 2026
·
Updated

WWBN AVideo is an open source video platform. In versions 29.0 and prior, objects/getCaptcha.php accepts the CAPTCHA length (ql) directly from the query string with no clamping or sanitization, letting any unauthenticated client force the server to generate a 1-character CAPTCHA word. Combined with a case-insensitive strcasecmp comparison over a ~33-character alphabet and the fact that failed validations do NOT consume the stored session token, an attacker can trivially brute-force the CAPTCHA on any endpoint that relies on Captcha::validation() (user registration, password recovery, contact form, etc.) in at most ~33 requests per session. Commit bf1c76989e6a9054be4f0eb009d68f0f2464b453 contains a fix.

Affected Software

2 affected components
WWBN AVideo<=29.0
WWBN AVideo<=29.0

Event History

Apr 21, 2026
CVE Published
via MITRE·10:21 PM
Data Sourced
via MITRE·10:21 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·11:16 PM
RemedyDescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-40935?

CVE-2026-40935 has a medium severity rating due to its potential for security bypass involving CAPTCHA.

2

How do I fix CVE-2026-40935?

To fix CVE-2026-40935, upgrade to a version of WWBN AVideo later than 29.0 to ensure proper handling of the CAPTCHA functionality.

3

What does CVE-2026-40935 involve?

CVE-2026-40935 involves a CAPTCHA bypass vulnerability that can be exploited through an attacker-controlled length parameter.

4

Which versions of AVideo are affected by CVE-2026-40935?

AVideo versions up to and including 29.0 are affected by CVE-2026-40935.

5

Is there a known exploit for CVE-2026-40935?

Yes, CVE-2026-40935 can be exploited due to missing token invalidation on failure, allowing attackers to bypass CAPTCHA protections.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203