Out-of-Bounds Read Vulnerability in UltraVNC by UltraVNC

CVE-2026-44041

What is CVE-2026-44041?

UltraVNC versions through 1.8.2.2 are vulnerable to an out-of-bounds read due to improper handling of wide-character strings in the vncWc2Mb() function. This vulnerability arises when a user supplies a WCHAR pointer that is not properly NUL-terminated before being passed to wcslen(). As a result, wcslen() may read beyond the intended buffer, resulting in potential information disclosure from adjacent memory regions or leading to a process crash. While the direct risk under typical usage conditions is limited, developers must implement strict input validation to mitigate the risk of exploitation.

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