CVE-2025-3863 is a vulnerability classified under CWE-862 (Missing Authorization) found in the Post Carousel Slider for Elementor plugin for WordPress, versions up to and including 1.6.0. The vulnerability arises because the process_wbelps_promo_form() function lacks proper capability checks, allowing any authenticated user with at least Subscriber-level privileges to invoke the plugin’s support form handler. This improper authorization flaw enables these users to send arbitrary emails to the site’s configured support email address. The vulnerability does not require elevated privileges beyond Subscriber, nor does it require user interaction beyond authentication. The CVSS 3.1 base score is 4.3 (medium), reflecting that the attack vector is network-based, with low attack complexity, requiring privileges, no user interaction, and impacting integrity but not confidentiality or availability. The flaw could be exploited to send unsolicited or malicious emails from the legitimate domain, potentially damaging the organization’s reputation or enabling phishing campaigns. No patches or fixes have been published yet, and no known exploits have been reported in the wild. The vulnerability affects all versions of the plugin up to 1.6.0, which is commonly used on WordPress sites to create carousel sliders for posts. The lack of authorization checks represents a common security oversight in WordPress plugin development, emphasizing the need for rigorous capability verification in all user-accessible functions.

The primary impact of this vulnerability is on the integrity of the affected WordPress sites’ email sending functionality. Authenticated users with minimal privileges can abuse the support form to send arbitrary emails, which could be used for spamming, phishing, or social engineering attacks leveraging the site’s trusted domain. This can lead to reputational damage, blacklisting of the site’s email domain, and potential downstream compromise if recipients are tricked into malicious actions. While the vulnerability does not directly expose sensitive data or disrupt service availability, the indirect consequences can be significant, especially for organizations relying on email communications for customer support or marketing. Attackers could also use this vector to bypass email filters by sending emails from a legitimate source. Organizations with many users having Subscriber or higher roles are at increased risk, as the attack requires authenticated access. The lack of known exploits suggests limited current threat activity, but the vulnerability’s presence in a popular WordPress plugin means it could be targeted in the future.

To mitigate this vulnerability, organizations should immediately audit user roles and permissions on WordPress sites using the Post Carousel Slider for Elementor plugin, restricting Subscriber-level accounts and above to trusted users only. Temporarily disabling or removing the plugin until a patch is available is advisable for high-risk environments. Monitoring outgoing emails for unusual patterns or spikes in support form submissions can help detect exploitation attempts. Implementing web application firewalls (WAFs) with custom rules to block unauthorized access to the vulnerable function’s endpoint may reduce risk. Site administrators should subscribe to security advisories from the plugin vendor and WordPress security communities to apply patches promptly once released. Additionally, applying the principle of least privilege by limiting user capabilities and employing multi-factor authentication can reduce the likelihood of unauthorized exploitation. Reviewing and hardening email server configurations to prevent spoofing and abuse will also help mitigate downstream impacts.