CVE-2026-72704: Rocq guard checker trusts corrupted recursive tree after transport (0 = 1 demonstrated) — 0-day

Posted by Jonathan Brossard on Oct 25 1. Summary ========== A soundness bug in the Rocq (formerly Coq) kernel's guard checker allows construction of a checked proof of False — and by extension, any proposition, including 0 = 1. The guard checker does not recheck the recursive tree (rectree) for an inductive type parameter after a transport (rewrite via eq_rect/rew) changes that parameter. A fixpoint applies a rewrite along a type equality to its recursive argument; the...

Published 26-Oct-2026 00:59 UTC · First seen 26-Oct-2026 00:58 UTC

Sources

• Open Source Security · 26-Oct-2026