Integer wraparound in psqlODBC SQLBindParameter allows an application, or an attacker who controls how many parameters the application binds on one statement, to corrupt heap memory. psqlODBC stores the binding count in a signed 16-bit field. Binding parameter number 32768 wraps that count to -32768. Binding parameter 32769 then writes about 2.5 MB of zeros starting 1.25 MB before the binding array, which crashes the application or leaves it running on a corrupted heap. Applications that build parameter lists from untrusted input, such as an IN (?, ?, ...) list, are exposed. Versions before psqlODBC 18.00.0005 are affected.