Key Information Vulnerability Type Heap Use-After-Free Affected Code Token parsing in → conversion Environment Operating System: Ubuntu 22.04 Compiler: clang 13.0.1 Sanitizers Used: AddressSanitizer (ASan) + UndefinedBehaviorSanitizer (UBSan) Build Commands Reproduction Steps Run the fuzzer with the crafted input file: Observed Behavior Program crashes; ASan/UBSan reports a heap use-after-free error. Root Cause Analysis tokenizes a line (via ), then converts a token to an integer (via ). During tokenization, the token vector/string is cleared/freed, but pointers/references to its buffer are still used in / , leading to use of already-freed memory. Attachments contains the proof-of-concept.