CVE-2025-48481 is a medium severity vulnerability affecting FreeScout, a free self-hosted help desk and shared mailbox software. The vulnerability arises from improper enforcement of behavioral workflow (CWE-841) related to account activation via email invitations. Specifically, in versions of FreeScout prior to 1.8.180, an attacker who possesses an unactivated email invitation containing an invite_hash parameter can exploit this flaw to self-activate their account. This is possible even if the account was previously blocked or deleted. The attacker leverages the invitation link embedded in the email to bypass intended restrictions and gain initial access to the system. This vulnerability allows unauthorized account activation without requiring user interaction beyond clicking the invitation link, and it requires only low privileges (an unactivated invitation) to exploit. The issue was addressed and patched in FreeScout version 1.8.180. The CVSS 4.0 base score is 6.1, reflecting a medium severity level, with network attack vector, low attack complexity, partial privileges required, no user interaction, and high impact on confidentiality. The vulnerability does not appear to have known exploits in the wild at this time.

For European organizations using FreeScout as their help desk or shared mailbox solution, this vulnerability could lead to unauthorized account activations, potentially allowing attackers to gain initial footholds within internal support systems. This could result in unauthorized access to sensitive customer support data, internal communications, or the ability to manipulate ticketing workflows. While the vulnerability does not directly allow privilege escalation beyond the initial account, it undermines access control policies and could be leveraged as a stepping stone for further attacks, such as social engineering or lateral movement within the network. Given that FreeScout is self-hosted, organizations with less mature patch management or security monitoring may be more vulnerable. The impact is particularly relevant for organizations handling sensitive customer data or regulated information, as unauthorized access could lead to data breaches or compliance violations under GDPR.

European organizations should immediately verify their FreeScout version and upgrade to version 1.8.180 or later to apply the official patch addressing this vulnerability. In addition to patching, organizations should audit existing user accounts and invitation workflows to detect any unauthorized activations or suspicious activity. Implementing stricter controls on invitation issuance and monitoring invitation link usage can help detect exploitation attempts. It is also advisable to enforce multi-factor authentication (MFA) on user accounts to reduce the risk of unauthorized access even if an account is improperly activated. Network segmentation of help desk systems and limiting access to invitation links via email security controls can further reduce exposure. Regularly reviewing logs for unusual account activation patterns and integrating alerts for such events will enhance detection capabilities. Finally, organizations should educate their staff about the risks of invitation link misuse and ensure secure handling of email invitations.