Out-of-bounds read/write in CPython remote debugging offset table handling

CVE-2026-5713 is a medium-severity vulnerability in CPython's remote debugging functionality affecting the profiling.sampling module in Python 3.15+ and asyncio introspection capabilities in Python 3.14+ (including "python -m asyncio ps" and "python -m asyncio pstree"). The issue arises because debug offset tables read from a target process were not sufficiently treated as untrusted input before being consumed by the unwinder and related introspection logic. A malicious or infected Python process can supply malformed sizes or offsets, leading the connecting privileged Python process to perform unintended memory reads and writes at attacker-influenced addresses. The associated fix validates _Py_DebugOffsets and AsyncioDebug structures when loaded, including section sizes used for fixed local buffers and offsets later dereferenced against local buffers or object views, rejecting malformed tables up front.