PatchSiren cyber security CVE debrief
CVE-2026-10552 jotis CVE debrief
The Blue Captcha plugin for WordPress, up to and including version 2.0.1, is vulnerable to Cross-Site Request Forgery (CSRF). This vulnerability stems from missing or incorrect nonce validation on the main admin panel and subpages, such as the Hall of Shame and Log. These pages accept a 'blcap_action' or 'action' parameter from $_REQUEST, which can lead to destructive operations like plugin uninstallation, log deletion, Hall of Shame entry removal, and adding arbitrary IP addresses to the block list. The lack of wp_verify_nonce(), check_admin_referer(), or check_ajax_referer() calls in the codebase allows unauthenticated attackers to perform these actions if they can trick a site administrator into performing an action, such as clicking on a link. The vulnerability has a CVSS score of 4.3 and is classified as MEDIUM severity.
- Vendor
- jotis
- Product
- Blue Captcha
- CVSS
- MEDIUM 4.3
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-24
- Original CVE updated
- 2026-06-25
- Advisory published
- 2026-06-24
- Advisory updated
- 2026-06-25
Who should care
Administrators of WordPress sites using the Blue Captcha plugin up to version 2.0.1 should be aware of this vulnerability. Given the nature of the CSRF attack, site administrators who may be tricked into performing unintended actions via links or other web requests are particularly at risk. Additionally, security teams monitoring for potential threats to WordPress installations should prioritize this vulnerability.
Technical summary
The Blue Captcha plugin for WordPress is vulnerable to Cross-Site Request Forgery (CSRF) due to inadequate validation of nonces. Specifically, the plugin's main admin panel and certain subpages (Hall of Shame and Log) do not properly validate 'blcap_action' or 'action' parameters from $_REQUEST. This oversight enables unauthenticated attackers to execute several destructive operations, including plugin uninstallation, log deletion, removal of Hall of Shame entries, and addition of arbitrary IP addresses to the banned list. The vulnerability exists because the plugin lacks calls to security functions like wp_verify_nonce(), check_admin_referer(), or check_ajax_referer(). The CVSS:3.1 vector for this vulnerability is AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N, reflecting a Medium severity with a score of 4.3.
Defensive priority
Defenders should prioritize updating the Blue Captcha plugin to a version that fixes the CSRF vulnerability. In the interim, site administrators should be cautious with links and web requests that could potentially trick them into performing unintended actions on the WordPress site.
Recommended defensive actions
- Update the Blue Captcha plugin to the latest version that addresses the CSRF vulnerability.
- Implement additional monitoring for suspicious activity related to the plugin's functionality.
- Educate site administrators on the risks of clicking on unverified links or performing actions based on unsolicited requests.
- Consider temporarily disabling or limiting access to the affected plugin's functionality until an update is applied.
- Review and enhance the site's security measures to prevent similar CSRF attacks in the future.
Evidence notes
The vulnerability details are based on information from the CVE record and the National Vulnerability Database (NVD). The CVE-2026-10552 record provides an overview of the vulnerability, including its description, CVSS score, and affected versions. The NVD entry offers additional technical details and references to the plugin's codebase, highlighting the specific areas lacking proper nonce validation.
Official resources
This article is AI-assisted and based on the supplied source corpus.