hCaptcha for WP <= 5.3.0 - Unauthenticated hCaptcha Bypass via Passster REST Unlock Endpoint
- ID
- WPSEC-2026-0022
- Plugin
- hCaptcha for WP (hcaptcha-for-forms-and-more)
- Affected
- from 3.3.0 before 5.4.0
- Remediation
- Update to 5.4.0 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
- Weakness
- CWE-693
- Usage
- Plugin Medium · Affected versions Medium among sites WPSec scans, 2026-10-22
- Attack surface
- hCaptcha for WP on WPSec AttackSurface
- Fix released
- Published
Description
The hCaptcha for WP plugin for WordPress is vulnerable to a protection mechanism bypass in versions 3.3.0 up to, and including, 5.3.0. The Passster integration verified hCaptcha only on Passster's legacy validate_input AJAX action. Current Passster (Content Protector) releases unlock protected content through the POST /passster/v1/unlock REST route instead, and the integration never checked that route. This makes it possible for unauthenticated attackers to submit unlimited password guesses for Passster-protected content without solving the hCaptcha challenge. Exploitation requires the Passster integration to be enabled together with a Passster version that unlocks content over REST.
References
- https://wpsec.com/vuln/WPSEC-2026-0022/
- https://plugins.svn.wordpress.org/hcaptcha-for-forms-and-more/tags/5.4.0/
- https://wordpress.org/plugins/hcaptcha-for-forms-and-more/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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