AIKIDO-2026-652269

TL;DR

The RBS parser's C lexer walks its input one character at a time and uses the active encoding's width lookup to decide how many bytes to advance. When the input contains a byte that is not valid for the encoding, the width lookup returns zero and the cursor never advances, so parsing a signature that includes an invalid byte enters a non-terminating loop while the global VM lock is held, and an invalid byte reached at the top level trips an internal assertion that aborts the process. Parsing untrusted or externally supplied signature text can therefore be forced to hang indefinitely or crash. The fix makes the lexer consume one byte when it meets an invalid sequence so parsing always makes progress, and surfaces the invalid byte as a normal parsing error instead of silently swallowing it or looping.