Security researchers have recently uncovered a critical vulnerability impacting Roundcube, a widely used webmail client. Tracked as CVE-2025-49113, this flaw allows for Remote Code Execution (RCE) under specific conditions.
The vulnerability stems from an unserialize() PHP Object Deserialization issue. This type of flaw occurs when an application deserializes untrusted data, which can be manipulated by an attacker to inject malicious code or objects into the application’s process. In this case, the exploit becomes possible post-authentication. This means an attacker must first successfully log into a Roundcube instance before they can potentially leverage the vulnerability to execute arbitrary code on the underlying server.
The impact of successful exploitation is severe, potentially leading to full compromise of the web server hosting the Roundcube instance. Given that Roundcube is often hosted on shared servers or servers containing sensitive data, the risk posed by CVE-2025-49113 is significant.
Affected versions include those prior to the fixed releases. It is absolutely crucial for administrators managing Roundcube instances to identify their current version.
The recommended action is immediate patching. Updates addressing CVE-2025-49113 have been released by the developers. Updating to the latest secure version is the most effective way to mitigate this post-authentication RCE vulnerability. Administrators should prioritize this update to protect their systems and user data from potential exploitation. Staying informed about such security advisories and applying patches promptly is fundamental to maintaining a secure online environment.
Source: https://www.offsec.com/blog/cve-2025-49113/
