In HCL Notes version 9 previous to release 9.0.1 FixPack 10 Interim Fix 8, version 10 previous to release 10.0.1 FixPack 6 and version 11 previous to 11.0.1 FixPack 1, a vulnerability in the input parameter handling of the Notes Client could potentially be exploited by an attacker resulting in a buffer overflow. This could enable an attacker to crash HCL Notes or execute attacker-controlled code on the client.