CVE-2025-48987 is a reflected Cross-Site Scripting (XSS) vulnerability identified in Revive Adserver versions 5.5.2, 6.0.1, and earlier. The root cause is improper neutralization of user-supplied input, which allows an attacker to craft malicious URLs or input that, when processed by the vulnerable server, reflect the injected script back to the user's browser. This script executes in the security context of the affected domain, potentially enabling attackers to steal session cookies, perform actions on behalf of the user, or manipulate displayed content. The vulnerability does not require authentication, lowering the barrier for exploitation, but does require user interaction such as clicking a malicious link. The CVSS 3.0 base score of 6.3 reflects a medium severity level, with attack vector being network-based, low attack complexity, no privileges required, but user interaction necessary. The impact spans confidentiality (e.g., theft of sensitive data), integrity (e.g., unauthorized actions), and availability (e.g., disruption via malicious scripts). No public exploits have been reported yet, but the presence of this vulnerability in widely used ad-serving software poses a risk to organizations relying on it for digital advertising. The lack of patch links indicates that fixes may be pending or not yet publicly released, emphasizing the need for vigilance and interim mitigations.

For European organizations, the exploitation of this vulnerability could lead to significant risks including unauthorized access to user sessions, theft of credentials, and manipulation of advertising content, potentially damaging brand reputation and user trust. Given that Revive Adserver is used to manage and deliver online advertisements, attackers could leverage this vulnerability to inject malicious ads or redirect users to phishing sites, amplifying the impact. Confidentiality breaches could expose sensitive client or user data, while integrity violations could distort advertising metrics or content. Availability impacts, though less direct, could arise from script-based disruptions or denial of service conditions triggered by malicious payloads. The medium severity suggests that while immediate catastrophic damage is unlikely, the cumulative effects on business operations, compliance with data protection regulations such as GDPR, and customer trust could be substantial if exploited at scale.

Organizations should monitor for official patches from Revive and apply updates promptly once available. In the interim, implement strict input validation and output encoding on all user-supplied data to prevent script injection. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Review and harden web application firewall (WAF) rules to detect and block malicious payloads targeting this vulnerability. Educate users and administrators about the risks of clicking untrusted links and encourage cautious behavior. Conduct regular security assessments and penetration testing focused on ad-serving infrastructure. Additionally, consider isolating the ad server environment to limit lateral movement in case of compromise and monitor logs for suspicious activities indicative of attempted exploitation.