CVE-2025-55064 is a Cross-site Scripting (XSS) vulnerability classified under CWE-79, affecting Priority Web versions 24.1 and below. The vulnerability arises from improper neutralization of user-supplied input during the generation of web pages, allowing malicious scripts to be injected and executed in the context of the victim's browser. This can lead to unauthorized actions such as session hijacking, defacement, or redirection to malicious sites. The CVSS 3.1 base score is 4.8 (medium), with an attack vector of network (remote), low attack complexity, requiring high privileges, and user interaction. The scope is changed, indicating that exploitation can affect components beyond the initially vulnerable one. Confidentiality and integrity impacts are limited, and availability is not affected. No patches or known exploits are currently available, but the vulnerability's presence in widely used Priority Web versions necessitates attention. The vulnerability requires an attacker to have high privileges on the system and to trick a user into interacting with malicious content, which may limit exploitation but does not eliminate risk. The lack of known exploits suggests this is a newly disclosed issue, but the potential for targeted attacks exists.

For European organizations, the impact of CVE-2025-55064 can be significant in environments where Priority Web is used for critical business functions. The XSS vulnerability can lead to unauthorized disclosure of sensitive information (confidentiality impact) and unauthorized modification of data or user sessions (integrity impact). While availability is not directly affected, successful exploitation could facilitate further attacks such as phishing or credential theft, potentially leading to broader compromise. Organizations in sectors such as finance, manufacturing, and government that rely on Priority Web may face increased risk of targeted attacks exploiting this vulnerability. The requirement for high privileges and user interaction reduces the likelihood of widespread automated exploitation but does not eliminate risks from insider threats or sophisticated attackers. Additionally, the shared nature of web applications means that multiple users could be impacted if an attacker successfully exploits the vulnerability, potentially leading to reputational damage and regulatory scrutiny under GDPR if personal data is exposed.

To mitigate CVE-2025-55064, European organizations should implement the following specific measures: 1) Apply any available patches or updates from Priority as soon as they are released; 2) Implement strict input validation and output encoding on all user-supplied data within Priority Web to prevent script injection; 3) Restrict user privileges to the minimum necessary, especially limiting high-privilege accounts that can exploit this vulnerability; 4) Employ Content Security Policy (CSP) headers to reduce the impact of potential XSS attacks by restricting script execution sources; 5) Conduct regular security awareness training to reduce the risk of successful social engineering that could trigger user interaction; 6) Monitor web application logs for unusual activity indicative of attempted XSS exploitation; 7) Use web application firewalls (WAFs) configured to detect and block XSS payloads targeting Priority Web; 8) Segregate Priority Web environments from critical network segments to limit lateral movement in case of compromise.