CVE-2025-53796 is a buffer over-read vulnerability classified under CWE-126, affecting the Windows Routing and Remote Access Service (RRAS) component in Microsoft Windows Server 2019 (specifically version 10.0.17763.0). The vulnerability arises due to improper bounds checking in RRAS, which allows an attacker to read memory beyond the intended buffer limits. This can lead to unauthorized disclosure of sensitive information over the network without requiring authentication, although user interaction is necessary to trigger the exploit. The vulnerability does not allow code execution or denial of service but compromises confidentiality by leaking potentially sensitive data. The CVSS 3.1 vector (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) indicates that the attack can be performed remotely over the network with low attack complexity, no privileges required, but requires user interaction. The scope remains unchanged, and the impact is high on confidentiality but none on integrity or availability. No known exploits have been reported in the wild, and no official patches have been linked yet, though Microsoft is expected to release updates. The vulnerability was reserved in July 2025 and published in September 2025, indicating recent discovery and disclosure.

For European organizations, this vulnerability poses a risk of sensitive information leakage from Windows Server 2019 systems running RRAS, which is commonly used for VPN and network routing services. Disclosure of sensitive data could include network configuration details, authentication tokens, or other critical information that attackers could leverage for further attacks or reconnaissance. This is particularly concerning for sectors with stringent data protection requirements such as finance, healthcare, and government. The lack of required privileges lowers the barrier for attackers, increasing the risk of exploitation in environments where RRAS is exposed to untrusted networks. However, the requirement for user interaction and absence of known exploits somewhat reduce immediate risk. Organizations relying heavily on Windows Server 2019 for remote access services may face increased exposure, potentially impacting confidentiality and compliance with data protection regulations like GDPR.

1. Apply Microsoft security updates promptly once patches for CVE-2025-53796 are released to address the buffer over-read in RRAS. 2. Until patches are available, restrict RRAS exposure by limiting access to trusted networks and implementing network segmentation to isolate RRAS servers from untrusted or public networks. 3. Employ strict firewall rules to control inbound traffic to RRAS services, minimizing the attack surface. 4. Monitor network traffic and logs for unusual or suspicious activity targeting RRAS, including unexpected connection attempts or malformed packets. 5. Educate users about the potential risks and the need to avoid interacting with suspicious network prompts or connections that could trigger the vulnerability. 6. Consider disabling RRAS if it is not essential or replacing it with alternative secure remote access solutions that do not exhibit this vulnerability. 7. Conduct regular vulnerability assessments and penetration testing focused on RRAS and related network services to identify and remediate exposure.