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

Advisory record · `GHSA-hg7g-56h5-5pqr`

- **Identifiers:** `GHSA-hg7g-56h5-5pqr` · `CVE-2026-40935` · `PKSA-k6wt-ck7m-8514`
- **State:** Confirmed
- **Severity:** CVSS 5.3 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-804](https://cwe.mitre.org/data/definitions/804.html)
- **Tags:** [CWE-804](https://agentprime.io/advisories/tag/cwe-804.md)
- **Published:** 14 Apr 2026
- **Updated:** 5 May 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 14 Apr 2026, 23:13 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `wwbn/avideo` (Packagist): affected `<=29.0`; no fixed version yet

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Wwbn/avideo versions up to and including 29.0 have a CAPTCHA bypass. The CAPTCHA generator accepts a length parameter from the query string without limits, so an unauthenticated attacker can force a one-character answer. Failed guesses also do not invalidate the stored answer, so the attacker can brute-force it in about 33 requests per session and pass the check on registration, password recovery, and contact endpoints. No fix is listed; the source suggests clamping the length parameter and consuming the stored answer on every validation attempt.

Written 3 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 5.3 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0022, the 12th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:25 UTC: First seen by agentprime
- 31 Oct 2026, 14:25 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-hg7g-56h5-5pqr)

## Sources

- [GitHub Advisory Database: GHSA-hg7g-56h5-5pqr](https://github.com/advisories/GHSA-hg7g-56h5-5pqr)
- [OSV: GHSA-hg7g-56h5-5pqr](https://osv.dev/vulnerability/GHSA-hg7g-56h5-5pqr)
- <https://github.com/WWBN/AVideo/security/advisories/GHSA-hg7g-56h5-5pqr>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-40935>
- <https://github.com/WWBN/AVideo/commit/bf1c76989e6a9054be4f0eb009d68f0f2464b453>
- <https://github.com/WWBN/AVideo>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-hg7g-56h5-5pqr>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-hg7g-56h5-5pqr/>. Everything for agents: <https://agentprime.io/llms.txt>.