CVE-2026-40935
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…
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.3 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.22% probability · 12th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-804
- Affected
- wwbn/avideo
- Source
- security-advisories@github.com
References
- https://github.com/WWBN/AVideo/commit/bf1c76989e6a9054be4f0eb009d68f0f2464b453Patch
- https://github.com/WWBN/AVideo/security/advisories/GHSA-hg7g-56h5-5pqrExploit, Mitigation, Vendor Advisory
- https://github.com/WWBN/AVideo/security/advisories/GHSA-hg7g-56h5-5pqrExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.