CVE-2026-20109 is a cross-site scripting vulnerability found in the web-based management interfaces of Cisco Packaged Contact Center Enterprise (Packaged CCE) and Cisco Unified Contact Center Enterprise (Unified CCE). The root cause is improper neutralization of user-supplied input during web page generation, which allows an attacker to inject malicious JavaScript code into specific pages of the management interface. This vulnerability affects numerous versions ranging from 10.5(1) through 15.0(1). An attacker must have valid administrative credentials to exploit this flaw, which limits the attack surface to authenticated users with high privileges. Successful exploitation could lead to execution of arbitrary scripts in the context of the victim’s browser session, potentially exposing sensitive information such as session tokens or enabling further attacks like session hijacking or privilege escalation within the management interface. The vulnerability has a CVSS v3.1 base score of 4.8, reflecting medium severity, with attack vector as network, low attack complexity, high privileges required, and user interaction needed. No public exploits have been reported yet, but the vulnerability could be leveraged in targeted attacks against organizations using these Cisco contact center products.

For European organizations, the impact of this vulnerability could be significant, especially for those relying on Cisco Packaged CCE or Unified CCE for customer service operations. Successful exploitation could compromise the confidentiality and integrity of administrative sessions, potentially exposing sensitive customer data or internal contact center configurations. This could lead to unauthorized changes in contact center operations, data leakage, or further lateral movement within the corporate network. Given the critical role of contact centers in customer engagement and regulatory compliance (e.g., GDPR), any compromise could result in reputational damage, regulatory penalties, and operational disruptions. The requirement for administrative credentials reduces the likelihood of widespread exploitation but insider threats or credential theft could enable attacks. The vulnerability does not impact availability directly but could indirectly affect service continuity if exploited.

To mitigate this vulnerability, organizations should apply any available Cisco patches or updates as soon as they are released. In the absence of patches, administrators should restrict access to the web-based management interface using network segmentation, VPNs, or IP whitelisting to limit exposure to trusted personnel only. Implement strong multi-factor authentication (MFA) for all administrative accounts to reduce the risk of credential compromise. Regularly audit and monitor administrative access logs for suspicious activity. Employ Content Security Policy (CSP) headers on the management interface to help mitigate the impact of XSS attacks. Educate administrators about phishing and social engineering risks to prevent credential theft. Additionally, consider using web application firewalls (WAFs) that can detect and block XSS payloads targeting the management interface. Finally, conduct periodic security assessments and penetration testing focused on the contact center environment to identify and remediate similar vulnerabilities proactively.