HCL Notes is susceptible to a Denial of Service vulnerability caused by improper validation of user-supplied input. A remote unauthenticated attacker could exploit this vulnerability using a specially-crafted email message to hang the client. Versions 9, 10 and 11 are affected.

HCL Notes is susceptible to a Buffer Overflow vulnerability in DXL due to improper validation of user input. A successful exploit could enable an attacker to crash Notes or execute attacker-controlled code on the client system.

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.

HCL Notes is vulnerable to an information leakage vulnerability through its support for the 'mailto' protocol. This vulnerability could result in files from the user's filesystem or connected network filesystems being leaked to a third party. All versions of HCL Notes 9, 10 and 11 are affected.

HCL Notes versions previous to releases 9.0.1 FP10 IF8, 10.0.1 FP6 and 11.0.1 FP1 is susceptible to a Stored Cross-site Scripting (XSS) vulnerability. An attacker could use this vulnerability to execute script in a victim's Web browser within the security context of the hosting Web site and/or steal the victim's cookie-based authentication credentials.