Medium · published January 23, 2026
A signed integer overflow in docopt.cpp v0.6.2 (LeafPattern::match in docopt_private.h) when merging occurrence counters (e.g., default LONG_MAX + first user "-v/--verbose") can cause counter wrap (negative/unbounded semantics) and lead to logic/policy bypass in applications that rely on occurrence-based limits, rate-gating, or safety toggles. In hardened builds (e.g., UBSan or -ftrapv), the overflow may also result in process abort (DoS).