CVE-2025-26841 is a Cross Site Scripting (XSS) vulnerability identified in the Everest Forms plugin for WordPress, specifically in versions before 3.0.9. This vulnerability allows an attacker to execute arbitrary code through a file upload mechanism. The core issue stems from insufficient input validation and sanitization of uploaded files, enabling malicious scripts to be injected and executed within the context of the victim's browser session. The vulnerability is categorized under CWE-79, which pertains to improper neutralization of input during web page generation. The CVSS v3.1 base score is 6.1, indicating a medium severity level. The attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), such as tricking a user into uploading or interacting with a malicious file. The scope is changed (S:C), meaning the vulnerability can affect resources beyond the initially vulnerable component. The impact on confidentiality and integrity is low (C:L, I:L), with no impact on availability (A:N). No known exploits are currently reported in the wild, and no official patches or vendor information are provided yet. The vulnerability could allow attackers to execute scripts that might steal session cookies, perform actions on behalf of the user, or deliver further payloads, potentially leading to account compromise or data leakage within affected WordPress sites using Everest Forms prior to version 3.0.9.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on WordPress websites with Everest Forms installed for customer interactions, lead generation, or internal workflows. Successful exploitation could lead to session hijacking, unauthorized actions on the website, or the injection of malicious content that damages the organization's reputation. Given the widespread use of WordPress in Europe, including by SMEs and public sector entities, the risk of data leakage or unauthorized access is notable. Although the vulnerability requires user interaction, phishing or social engineering campaigns could be used to exploit it. The medium severity score reflects that while the vulnerability does not directly cause system downtime or full system compromise, it undermines trust and confidentiality, which are critical under GDPR regulations. Organizations could face compliance issues if personal data is exposed or manipulated due to this vulnerability.

European organizations should immediately verify if they use Everest Forms on their WordPress sites and identify the version in use. Upgrading to version 3.0.9 or later, once available, is the primary mitigation step. In the absence of an official patch, organizations should implement strict input validation and sanitization on file uploads at the web application firewall (WAF) or reverse proxy level to block suspicious file types or scripts. Additionally, disabling file uploads in forms where not necessary can reduce risk. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. Regularly audit and monitor logs for unusual file upload activity or user interactions. User awareness training to recognize phishing attempts that could trigger the vulnerability is also recommended. Finally, ensure that WordPress core, plugins, and themes are kept up to date to minimize exposure to similar vulnerabilities.