CWE-804BaseIncomplete
Guessable CAPTCHA
The product uses a CAPTCHA challenge, but the challenge can be guessed or automatically recognized by a non-human actor.
Open in catalog with CWE filter →Related CAPECs
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Related vulnerabilities
CVE-2022-1801The Very Simple Contact Form WordPress plugin before 11.6 exposes the solution to the captcha in the rendered contact form, both as hidden input fields and as plain text in the page, making it very easy for bots to bypass the captcha check, rendering the page a likely target for spam bots.
CVE-2026-49953Discuz! X5.0 releases 20260320 through 20260610 contains a CAPTCHA bypass vulnerability that allows unauthenticated remote attackers to defeat challenge controls by exploiting limited complexity and predictable character sets in generated CAPTCHA images. Attackers can train a custom optical character recognition model against collected CAPTCHA samples to reliably predict challenge text, bypassing protections on login, registration, and other functionality from automated abuse.
CVE-2025-32036DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. The algorithm used to generate the captcha image shows the least complexity of the desired image. For this reason, the created image can be easily read by OCR tools, and the intruder can send automatic requests by building a robot and using this tool. This vulnerability is fixed in 9.13.8.
CVE-2026-27411Guessable CAPTCHA vulnerability in jp-secure SiteGuard WP Plugin siteguard allows Functionality Bypass.This issue affects SiteGuard WP Plugin: from n/a through <= 1.7.9.
CVE-2026-40935WWBN 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.
CVE-2025-70129If the anti spam-captcha functionality in PluXml versions 5.8.22 and earlier is enabled, a captcha challenge is generated with a format that can be automatically recognized for articles, such that an automated script is able to solve this anti-spam mechanism trivially and publish spam comments. The details of captcha challenge are exposed within document body of articles with comments & anti spam-captcha functionalities enabled, including "capcha-letter", "capcha-word" and "capcha-token" which can be used to construct a valid post request to publish a comment. As such, attackers can flood articles with automated spam comments, especially if there are no other web defenses available.
CVE-2025-1262The Advanced Google reCaptcha plugin for WordPress is vulnerable to CAPTCHA Bypass in versions up to, and including, 1.27 . This makes it possible for unauthenticated attackers to bypass the Built-in Math Captcha Verification.
CVE-2024-31295Guessable CAPTCHA vulnerability in BestWebSoft Captcha by BestWebSoft allows Functionality Bypass.This issue affects Captcha by BestWebSoft: from n/a through 5.2.0.
CVE-2024-30540Guessable CAPTCHA vulnerability in Guido VS Contact Form allows Functionality Bypass.This issue affects VS Contact Form: from n/a through 14.7.
CVE-2023-6963The Getwid – Gutenberg Blocks plugin for WordPress is vulnerable to CAPTCHA Bypass in versions up to, and including, 2.0.4. This makes it possible for unauthenticated attackers to bypass the Captcha Verification of the Contact Form block by omitting 'g-recaptcha-response' from the 'data' array.
CVE-2022-4036The Appointment Hour Booking plugin for WordPress is vulnerable to CAPTCHA bypass in versions up to, and including, 1.3.72. This is due to the use of insufficiently strong hashing algorithm on the CAPTCHA secret that is also displayed to the user via a cookie.