CAPTCHA Bypass in WWBN/AVideo via Attacker-Controlled Length Parameter and Missing Token Invalidation on Failure

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

EPSS

• CVE-2026-40935: 0.22% estimated exploitation activity in the next 30 days; percentile 12.29 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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. Details Three cooperating flaws in objects/getCaptcha.php and objects/captcha.php reduce CAPTCHA protection to a deterministic bypass. 1. External control of CAPTCHA strength (objects/getCaptcha.php:7) There is no minimum, no type-check, and no clamping. Requesting /objects/getCaptcha.php?ql=1 causes the server to generate a single-character word and save it to the attacker's own PHP session. 2. Small alphabet…

Published by the source

14 Apr 2026, 23:13 UTC

Last modified by the source

24 Apr 2026, 20:32 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-hg7g-56h5-5pqr

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# Patch Next advisory brief: CVE-2026-40935

Advisory: CAPTCHA Bypass in WWBN/AVideo via Attacker-Controlled Length Parameter and Missing Token Invalidation on Failure
IDs: CVE-2026-40935, GHSA-hg7g-56h5-5pqr
Record: https://patchnext.com/advisories/cve-2026-40935 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist wwbn/avideo: affected <= 29.0

## Suggested inspection (read-only)
- Packagist wwbn/avideo: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on wwbn/avideo.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-hg7g-56h5-5pqr (GitHub-reviewed advisory GHSA-hg7g-56h5-5pqr lists affected ranges: Packagist wwbn/avideo >=0 <=29.0)

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