An issue exists in ECCurve.java and ECCurve.cs in Bouncy Castle Java (BC Java) prior to 1.78, BC Java LTS prior to 2.73.6, BC-FJA prior to 1.0.2.5, and BC C# .Net prior to 2.3.1. Importing an EC certificate with crafted F2m parameters can lead to excessive CPU consumption during the evaluation of the curve parameters.