---
id: CVE-2026-113667
aliases:
  - GHSA-44qr-rrjg-2cqq
title: 'ApostropheCMS: CAPTCHA response token not URL-encoded'
summary: 'ApostropheCMS: CAPTCHA response token not URL-encoded'
severity: medium
cvss: 5.3
cwe:
  - CWE-116
vendor: apostrophecms
product: '@apostrophecms/form'
ecosystem: npm
affected:
  - '@apostrophecms/form < 1.5.5'
  - '@apostrophecms/login-recaptcha < 1.2.1'
  - '@apostrophecms/login-hcaptcha < 1.3.0'
patched:
  - '@apostrophecms/form 1.5.5'
  - '@apostrophecms/login-recaptcha 1.2.1'
  - '@apostrophecms/login-hcaptcha 1.3.0'
published: '2026-10-20'
updated: '2026-10-20'
sourceUpdated: '2026-10-20T18:05:36Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-44qr-rrjg-2cqq'
references:
  - url: >-
      https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-44qr-rrjg-2cqq
  - url: >-
      https://github.com/apostrophecms/apostrophe/commit/9500b8b0e1d630d5e07fbb5fd2c25ed0943845ce
  - url: >-
      https://github.com/apostrophecms/apostrophe/commit/f84fd41cbf6c22eb8d0008fc9c25df1f7130b350
  - url: >-
      https://github.com/apostrophecms/apostrophe/releases/tag/@apostrophecms/form@1.5.5
  - url: 'https://github.com/advisories/GHSA-44qr-rrjg-2cqq'
tags:
  - ghsa
  - npm
  - cve.org
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N'
cvssSource: cna
ingestedAt: '2026-10-20T18:14:37.212Z'
---

## Overview

**Summary**
Form and login CAPTCHA verification interpolate the user-supplied widget token unencoded into the server-side verification URL/body, allowing a crafted token to inject query parameters into the reCAPTCHA/hCaptcha verify request.

**Details**
- `packages/form/lib/recaptcha.js:39` — `recaptchaUri = 'https://www.google.com/recaptcha/api/siteverify?secret=${recaptchaSecret}&response=${input.recaptcha}'`
- `packages/login-recaptcha/index.js:44` — same pattern for login
- `packages/login-hcaptcha/index.js:47` — `body: 'response=${token}&secret=${secret}'`

**PoC**
```
input.recaptcha = 'attacker_token&secret=INJECTED_SECRET&something=1'
→ resulting verify URL:
   https://www.google.com/recaptcha/api/siteverify?secret=<real>&response=attacker_token&secret=INJECTED_SECRET&something=1
# (replicated exactly from recaptcha.js:39)
```

**Impact**
Low: a crafted token smuggles extra `key=value` pairs (`secret`, extra `response`) into the outbound verify call, forcing verification failures (DoS of the captcha gate and of captcha-gated login/form flows) and enabling automated bypass probing; no secret exfiltration.

**Remediation** — Build the verify request with `URL` + `searchParams` (or `encodeURIComponent` on both `secret` and `response`), and validate the token against `^[A-Za-z0-9._-]{1,2048}$` before use.

## Affected packages

- `@apostrophecms/form < 1.5.5`
- `@apostrophecms/login-recaptcha < 1.2.1`
- `@apostrophecms/login-hcaptcha < 1.3.0`

## Remediation

Upgrade to a patched release:

- `@apostrophecms/form 1.5.5`
- `@apostrophecms/login-recaptcha 1.2.1`
- `@apostrophecms/login-hcaptcha 1.3.0`