CVE-2025-70960 identifies a stored cross-site scripting (XSS) vulnerability in the Forums module of Tendenci CMS version 15.3.7. Stored XSS vulnerabilities occur when malicious input is saved by the application and later rendered in users' browsers without proper sanitization or encoding. In this case, attackers can inject crafted JavaScript or HTML payloads into forum posts or comments, which are then executed in the context of other users viewing the forum. This can lead to a range of attacks including session hijacking, cookie theft, defacement, or redirecting users to malicious sites. The vulnerability does not require authentication, increasing its risk profile, and affects all users who access the vulnerable forum pages. Tendenci CMS is an open-source content management system often used by organizations to manage membership and community forums. Although no public exploits are currently known, the vulnerability's presence in a widely accessible module makes it a critical concern. The absence of a CVSS score means severity must be inferred from the nature of the vulnerability: stored XSS is typically high risk due to persistent impact and ease of exploitation. The lack of patch links suggests that an official fix may not yet be available, emphasizing the need for interim mitigations. The vulnerability's impact extends to confidentiality, integrity, and potentially availability if exploited to deliver malware or conduct phishing attacks. European organizations using Tendenci CMS should assess their exposure and implement mitigations promptly.

For European organizations, this vulnerability can lead to significant security breaches including unauthorized access to user accounts, theft of sensitive information, and reputational damage. Organizations relying on Tendenci CMS for forums or community engagement risk exposure of their users to malicious scripts that can hijack sessions or steal credentials. This can result in loss of trust, regulatory non-compliance (especially under GDPR if personal data is compromised), and potential financial losses. The persistent nature of stored XSS means that once exploited, the malicious payload can affect multiple users over time, amplifying the impact. Additionally, attackers could leverage this vulnerability to distribute malware or conduct phishing campaigns targeting European users. The lack of an official patch increases the urgency for organizations to implement compensating controls. Given the widespread use of web-based community platforms in sectors such as education, non-profits, and professional associations across Europe, the potential attack surface is considerable.

1. Immediately audit all user-generated content in the Forums module for suspicious or malicious scripts and remove any identified payloads. 2. Implement strict input validation and output encoding on all forum inputs to prevent injection of executable scripts. 3. Apply Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 4. Restrict forum posting privileges to trusted users or require moderation before posts are published to reduce risk exposure. 5. Monitor forum activity for unusual behavior indicative of exploitation attempts. 6. If possible, isolate the forum module or disable it temporarily until an official patch is released. 7. Engage with the Tendenci CMS community or vendor to obtain updates or patches addressing this vulnerability. 8. Educate users about the risks of clicking suspicious links or interacting with unexpected forum content. 9. Regularly back up forum data to enable recovery in case of compromise. 10. Consider deploying web application firewalls (WAF) with rules to detect and block XSS payloads targeting the forum module.