CVE-2025-68460 is a vulnerability identified in Roundcube Webmail, a widely used open-source webmail client, affecting versions prior to 1.5.12 and 1.6 before 1.6.12. The root cause is improper encoding or escaping of output in the HTML style sanitizer component, categorized under CWE-116. This weakness allows maliciously crafted input to bypass sanitization, leading to information disclosure. Specifically, the sanitizer fails to correctly handle certain HTML style attributes, enabling attackers to extract sensitive data from the webmail interface. The vulnerability is exploitable remotely over the network without requiring any authentication or user interaction, increasing its risk profile. The CVSS 3.1 score of 7.2 reflects a high severity, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and a scope change (S:C), indicating that the vulnerability affects components beyond the initially vulnerable module. The impact includes partial loss of confidentiality and integrity but no impact on availability. Although no known exploits have been reported in the wild yet, the ease of exploitation and the critical nature of email systems make this a significant threat. The lack of available patches at the time of reporting necessitates urgent attention from administrators to update to fixed versions once released or apply interim mitigations.

For European organizations, this vulnerability poses a substantial risk to the confidentiality and integrity of email communications, which are critical for business operations and regulatory compliance such as GDPR. Information disclosure could lead to leakage of sensitive corporate or personal data, potentially resulting in reputational damage, financial loss, and legal consequences. Since Roundcube is commonly deployed in various sectors including government, finance, healthcare, and education across Europe, the impact could be widespread. The vulnerability’s network-exploitable nature means attackers can target exposed webmail interfaces remotely, increasing the attack surface. The scope change in the vulnerability suggests that exploitation could affect components beyond the immediate webmail interface, potentially compromising broader system elements. Organizations relying on vulnerable versions without timely patching may face increased risk of targeted attacks or data breaches. The absence of known exploits in the wild currently reduces immediate threat but does not eliminate the risk, especially as exploit development could follow disclosure.

European organizations should immediately inventory their Roundcube Webmail deployments to identify affected versions prior to 1.5.12 and 1.6 before 1.6.12. They should plan and execute upgrades to the latest patched versions as soon as they become available. Until patches are applied, administrators can implement strict input validation and output encoding policies at the web server or application firewall level to block suspicious HTML style attributes. Disabling or restricting the use of custom styles in emails may reduce exposure. Monitoring webmail access logs for unusual patterns or repeated requests targeting the sanitizer component can help detect exploitation attempts. Employing network segmentation to limit access to webmail interfaces and enforcing strong access controls can reduce risk. Additionally, organizations should review and update incident response plans to include scenarios involving webmail information disclosure. Regular security awareness training for users about phishing and suspicious emails remains important to mitigate secondary attack vectors.