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CWE-804
Guessable CAPTCHA
The product uses a CAPTCHA challenge, but the challenge can be guessed or automatically recognized by a non-human actor.
CVE-2026-27411 (GCVE-0-2026-27411)
Vulnerability from cvelistv5 – Published: 2026-03-05 05:54 – Updated: 2026-04-29 09:51
VLAI
Title
WordPress SiteGuard WP plugin plugin <= 1.7.9 - Captcha Bypass vulnerability
Summary
Guessable 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.
Severity
5.4 (Medium)
5.3 (Medium)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-804 - Guessable CAPTCHA
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://patchstack.com/database/Wordpress/Plugin/… | vdb-entry |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| jp-secure | SiteGuard WP Plugin |
Affected:
0 , ≤ 1.7.9
(custom)
|
Date Public
2026-04-22 14:19
Credits
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CVE-2026-40935 (GCVE-0-2026-40935)
Vulnerability from cvelistv5 – Published: 2026-04-21 22:21 – Updated: 2026-04-22 18:36
VLAI
Title
WWBN/AVideo has CAPTCHA Bypass via Attacker-Controlled Length Parameter and Missing Token Invalidation on Failure
Summary
WWBN 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.
Severity
5.3 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-804 - Guessable CAPTCHA
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/WWBN/AVideo/security/advisorie… | x_refsource_CONFIRM |
| https://github.com/WWBN/AVideo/commit/bf1c76989e6… | x_refsource_MISC |
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CVE-2026-49953 (GCVE-0-2026-49953)
Vulnerability from cvelistv5 – Published: 2026-06-15 18:45 – Updated: 2026-06-16 09:48 X_Open Source
VLAI
Title
Discuz! X5.0 CAPTCHA Bypass via Predictable Character Set
Summary
Discuz! 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.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-804 - Guessable CAPTCHA
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://karmainsecurity.com/KIS-2026-10 | technical-description |
| https://karmainsecurity.com/chaining-bugs-in-disc… | exploit |
| https://www.vulncheck.com/advisories/discuz-x5-0-… | third-party-advisory |
| http://seclists.org/fulldisclosure/2026/Jun/4 |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Discuz! | Discuz! X5.0 |
Affected:
20260320 , ≤ 20260610
(date)
|
Date Public
2026-06-13 00:00
Credits
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No mitigation information available for this CWE.
No CAPEC attack patterns related to this CWE.