CVE-2025-62871 identifies a Cross-Site Request Forgery (CSRF) vulnerability in the Just TinyMCE Custom Styles plugin developed by Alex Prokopenko / JustCoded, affecting versions up to and including 1.2.1. CSRF vulnerabilities occur when an attacker tricks an authenticated user into submitting a malicious request unknowingly, exploiting the trust a web application places in the user's browser. In this case, the vulnerability allows unauthorized commands to be executed within the context of the authenticated user, potentially altering plugin settings or injecting malicious styles. The plugin is commonly used to extend the TinyMCE editor with custom styling options, often integrated into content management systems like WordPress. No CVSS score has been assigned yet, and no public exploits are known, but the vulnerability is published and recognized by Patchstack. The absence of anti-CSRF protections such as tokens or origin validation in the plugin's request handling is the root cause. This vulnerability primarily threatens the integrity of the affected systems by enabling unauthorized configuration changes that could lead to further compromise or defacement. The attack requires the victim to be authenticated but does not require additional user interaction beyond visiting a malicious page. The scope is limited to installations using the vulnerable plugin versions. The vulnerability was reserved in late October 2025 and published in December 2025, indicating recent discovery and disclosure.

For European organizations, the impact of CVE-2025-62871 can be significant, especially for those relying on WordPress or other CMS platforms that utilize the Just TinyMCE Custom Styles plugin. Successful exploitation could allow attackers to modify editor styles or configurations, potentially leading to website defacement, unauthorized content injection, or further exploitation vectors such as persistent cross-site scripting (XSS). This undermines the integrity and trustworthiness of web content, which can damage brand reputation and user trust. Additionally, unauthorized changes could facilitate phishing or malware distribution through compromised web pages. The vulnerability does not directly impact confidentiality or availability but can be a stepping stone for more severe attacks. Organizations in sectors with high regulatory scrutiny, such as finance, healthcare, and government, may face compliance risks if exploited. Since the attack requires an authenticated session, organizations with many users or editors are at higher risk. The lack of known exploits currently provides a window for proactive mitigation before widespread abuse occurs.

To mitigate CVE-2025-62871, organizations should take the following specific actions: 1) Immediately check for updates or patches from the vendor Alex Prokopenko / JustCoded and apply them as soon as they become available. 2) If patches are not yet available, consider disabling or removing the Just TinyMCE Custom Styles plugin temporarily to eliminate the attack surface. 3) Implement web application firewall (WAF) rules to detect and block suspicious POST requests that do not include valid anti-CSRF tokens or originate from untrusted sources. 4) Review and enforce strict Content Security Policy (CSP) headers to limit the impact of potential content injection. 5) Educate users and administrators about the risks of CSRF and encourage cautious behavior when clicking on unknown links, especially while authenticated. 6) Monitor web server and application logs for unusual or unauthorized requests targeting the plugin endpoints. 7) Conduct regular security assessments and penetration testing focusing on CSRF and related web vulnerabilities. 8) Consider implementing multi-factor authentication (MFA) to reduce the risk of session hijacking that could facilitate exploitation.