CVE-2025-48986 is an authorization bypass vulnerability identified in Revive Adserver versions 5.5.2, 6.0.1, and earlier. The flaw allows an attacker who has already authenticated to the system to manipulate the email addresses of other users without proper authorization controls. This manipulation is critical because it enables the attacker to trigger the 'forgot password' functionality for the victim's account, redirecting password reset links to an attacker-controlled email address. Consequently, the attacker can take over other users' accounts, gaining unauthorized access to potentially sensitive advertising campaign data and administrative functions. The vulnerability stems from insufficient access control checks on user email modification endpoints. The CVSS 3.0 score of 8.8 reflects the network exploitable nature (AV:N), low attack complexity (AC:L), requiring privileges (PR:L) but no user interaction (UI:N), with high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Although no exploits have been reported in the wild yet, the vulnerability poses a significant risk due to the ease of exploitation once authenticated. Revive Adserver is widely used by digital marketing and advertising platforms to manage ad campaigns, making this vulnerability particularly impactful for organizations relying on it for revenue generation and user data management. The vulnerability was reserved in May 2025 and published in November 2025, indicating a recent disclosure with likely forthcoming patches.

For European organizations, the impact of CVE-2025-48986 can be severe. Successful exploitation leads to account takeover, which compromises the confidentiality of user data and advertising campaign information. Attackers can manipulate ad delivery, potentially causing financial losses, reputational damage, and exposure of sensitive business intelligence. Integrity of advertising data and campaign configurations can be undermined, disrupting marketing operations. Availability may also be affected if attackers disrupt or lock out legitimate users. Given the role of digital advertising in European economies and the GDPR regulatory environment, unauthorized access to user data could result in regulatory penalties and loss of customer trust. Organizations with multi-user Revive Adserver deployments are particularly vulnerable, as the attack requires a logged-in user but can escalate privileges by hijacking other accounts. The absence of known exploits in the wild suggests a window for proactive defense, but the high CVSS score underscores the urgency for mitigation.

1. Apply official patches from Revive as soon as they become available to address the authorization bypass. 2. Until patches are deployed, restrict user privileges to the minimum necessary, especially limiting access to user management functions. 3. Implement strong monitoring and alerting on changes to user email addresses and password reset requests to detect suspicious activity early. 4. Enforce multi-factor authentication (MFA) for all users to reduce the risk of account takeover even if email addresses are changed. 5. Conduct regular audits of user accounts and permissions within Revive Adserver to identify anomalies. 6. Segment the network and isolate the adserver environment to limit lateral movement in case of compromise. 7. Educate users about phishing and social engineering risks that could facilitate initial login by attackers. 8. Review and harden the configuration of the forgot password functionality, if possible, to add additional verification steps.