CVE-2025-3863 is a medium-severity vulnerability affecting the Post Carousel Slider for Elementor WordPress plugin developed by plugindevs. The vulnerability arises from a missing authorization check in the function process_wbelps_promo_form(), which handles the plugin's support form submissions. Specifically, the plugin fails to verify whether the authenticated user has the appropriate capabilities before allowing the function to execute. This flaw exists in all versions up to and including 1.6.0. As a result, any authenticated user with at least Subscriber-level access—which is a very low privilege level in WordPress—can trigger the support form handler to send arbitrary emails to the site’s configured support address. The vulnerability does not require user interaction beyond authentication, and the attack vector is remote over the network (AV:N). The CVSS v3.1 base score is 4.3, reflecting low complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), and limited impact on integrity (I:L) without affecting confidentiality or availability. There are no known exploits in the wild as of the publication date (June 26, 2025), and no patches have been released yet. The vulnerability is classified under CWE-862 (Missing Authorization), indicating a failure to properly restrict access to a sensitive function. The impact is primarily limited to the integrity of email communications sent from the vulnerable site, potentially enabling attackers to send unauthorized emails to the support address, which could be leveraged for social engineering, phishing, or spam campaigns originating from a trusted domain. However, the vulnerability does not directly expose sensitive data or allow code execution or site takeover.

For European organizations using WordPress websites with the Post Carousel Slider for Elementor plugin (version 1.6.0 or earlier), this vulnerability poses a risk of unauthorized email sending from their domains. This could undermine trust in corporate communications, damage brand reputation, and facilitate phishing or social engineering attacks targeting internal support teams or external partners. Organizations in sectors with high reliance on customer support portals—such as e-commerce, finance, and public services—may be particularly impacted. While the vulnerability does not allow data exfiltration or site compromise, the ability to send arbitrary emails from a legitimate domain can be exploited to bypass email filters and increase the success rate of targeted attacks. Additionally, the low privilege requirement means that any compromised or malicious subscriber-level account can be leveraged, increasing the attack surface. Given the widespread use of WordPress in Europe and the popularity of Elementor plugins, the potential for exploitation exists especially in small to medium enterprises that may not have rigorous plugin update policies. The lack of patches increases exposure time, and the absence of known exploits suggests the threat is currently theoretical but could be weaponized in the future.

1. Immediate mitigation involves restricting or disabling the Post Carousel Slider for Elementor plugin until an official patch is released. 2. Monitor and audit user accounts with Subscriber-level access to detect any suspicious activity, including unusual email sending patterns. 3. Implement strict email filtering and monitoring on the support email addresses to detect and block unauthorized or anomalous messages originating from the website domain. 4. Employ Web Application Firewalls (WAFs) with custom rules to detect and block requests to the vulnerable function or unusual POST requests targeting the plugin’s support form handler. 5. Enforce the principle of least privilege by reviewing and minimizing the number of users with Subscriber or higher access, and consider implementing multi-factor authentication (MFA) for all authenticated users to reduce the risk of account compromise. 6. Prepare to apply patches promptly once available and subscribe to vendor or security mailing lists for updates. 7. Conduct penetration testing or vulnerability scanning focused on WordPress plugins to identify similar authorization issues proactively. 8. Educate support teams to recognize potential phishing attempts that may originate from compromised internal systems.