RootCauseunvalidated

`where` pointer before the base-256 marker check — Two pre-processing steps advance the `where` pointer. Tension: the decoder is entered without verifying ≥2 bytes remain.

d2bf6cae-87b5-4a10-8cd5-a736839e3c76

where pointer before the base-256 marker check — Two pre-processing steps advance the where pointer. Tension: the decoder is entered without verifying ≥2 bytes remain.