CVE-2026-40935 Details
Description
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.
A vulnerability in WWBN AVideo versions through 29.0 allows for CAPTCHA bypassing on several endpoints. The issue arises in 'objects/getCaptcha.php', which accepts the CAPTCHA length parameter directly from the query string without proper validation. This flaw enables unauthenticated users to force the server to generate a one-character CAPTCHA. Additionally, the CAPTCHA validation process, handled by 'objects/captcha.php', uses a case-insensitive string comparison over a limited alphabet of approximately 33 characters. Failed validation attempts do not invalidate the session token, allowing attackers to brute-force the CAPTCHA with minimal effort. This vulnerability affects endpoints that rely on 'Captcha::validation()', such as user registration, password recovery, and contact forms.
Users are advised to update to the latest version of WWBN AVideo, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Apr 22, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/WWBN/AVideo/security/advisories/GHSA-hg7g-56h5-5pqr | CISA-ADP | ExploitMitigationVendor Advisory |
| https://github.com/WWBN/AVideo/commit/bf1c76989e6a9054be4f0eb009d68f0f2464b453 | [email protected] | Patch |
| https://github.com/WWBN/AVideo/security/advisories/GHSA-hg7g-56h5-5pqr | [email protected] | ExploitMitigationVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-804 | Guessable CAPTCHA | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| wwbn avideo | <= 29.0 |
CPE
Remediation
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Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Apr 23, 2026 | Initial Analysis | [email protected] |
| Apr 22, 2026 | CVE Modified | CISA-ADP |
| Apr 21, 2026 | New CVE Received | [email protected] |