CVE-2026-20824 is a vulnerability identified in Microsoft Windows 10 Version 1607 (build 14393) that involves a protection mechanism failure within the Windows Remote Assistance feature. The underlying weakness is categorized under CWE-693, which pertains to protection mechanism failures where security controls do not function as intended. This flaw allows an unauthorized local attacker to bypass a security feature, potentially gaining unauthorized access to confidential information. The attack vector is local (AV:L), requiring no privileges (PR:N) but does require user interaction (UI:R), such as convincing a user to accept a Remote Assistance session or similar action. The scope is unchanged (S:U), meaning the impact is limited to the vulnerable component without affecting other system components. The vulnerability impacts confidentiality (C:H) but does not affect integrity or availability. The CVSS v3.1 base score is 5.5, indicating medium severity. No known exploits are reported in the wild, and no official patches have been released yet. The vulnerability likely stems from improper enforcement or bypass of security controls designed to protect Remote Assistance sessions, potentially allowing attackers to access sensitive data or escalate privileges locally. Given the age of the affected Windows version, this vulnerability primarily impacts legacy systems that have not been updated to newer Windows 10 versions or Windows 11.

The primary impact of CVE-2026-20824 is unauthorized disclosure of confidential information due to bypassing a security feature in Windows Remote Assistance. Since the attack requires local access and user interaction, the risk is higher in environments where users have physical or remote local access and can be socially engineered. Organizations running legacy Windows 10 Version 1607 systems may face increased risk of data leakage or unauthorized access to sensitive information. Although the vulnerability does not affect system integrity or availability, the confidentiality breach could lead to further attacks or data exposure. This is particularly concerning for organizations with strict data protection requirements or those operating in regulated industries. The lack of known exploits in the wild reduces immediate risk, but the absence of patches means the vulnerability remains open for potential exploitation. Overall, the impact is moderate but could be significant in environments with many legacy endpoints or insufficient endpoint security controls.

1. Restrict local access to systems running Windows 10 Version 1607 to trusted users only, minimizing the risk of local exploitation. 2. Disable or tightly control Windows Remote Assistance functionality via Group Policy or system settings to reduce the attack surface. 3. Educate users about the risks of accepting unsolicited Remote Assistance requests and implement strict user interaction policies. 4. Monitor systems for unusual Remote Assistance activity or attempts to bypass security features. 5. Apply any forthcoming security updates or patches from Microsoft promptly once available. 6. Consider upgrading affected systems to a supported, more secure Windows version to eliminate exposure to legacy vulnerabilities. 7. Employ endpoint detection and response (EDR) tools to detect suspicious local privilege escalation or bypass attempts. 8. Implement application whitelisting and least privilege principles to limit the impact of local attacks.