Worked on the Azure/azure-sdk-for-cpp repository to address a critical memory safety vulnerability in the Base64 decoding logic. Focused on C++ development with an emphasis on security engineering and unit testing, the work involved preventing out-of-bounds memory access by ensuring input bytes were treated as unsigned and validating sentinel values before bitwise operations. Enhanced error handling provided standardized and clear messages for invalid input, while comprehensive test coverage was added to catch malformed data and guard against regressions. The changes maintained backward compatibility for valid inputs, strengthening the decoder’s resilience and reducing risk for downstream services relying on encoded data.