Ravencoin — KAWPOW PoW Consensus Flaw & Chain Rollback

August 7–11, 2026 — Ravencoin's KAWPOW proof-of-work consensus mechanism was exploited via an input validation flaw, causing invalid blocks to be accepted by vulnerable nodes and triggering a 3-4 day chain rollback.

Vulnerability: Ravencoin's C++ codebase (derived from Bitcoin) failed to validate the nHeight field in KAWPOW block headers against the block's actual position in the chain. An attacker could submit blocks with arbitrary nHeight values that passed the PoW check — nodes accepted them as valid chain continuations.

2026-08-07, 15:44:01 UTC: First known invalid block mined at height 4,487,776. Invalid blocks continue to propagate silently over the following days.

Aug 8 (private): The vulnerability was reported to the Ravencoin team via responsible disclosure.

Aug 10–11, 2026: Ravencoin team publicly discloses the consensus vulnerability (@Ravencoin tweet 2086862580014850412). Network alert issued. RVN price falls ~18-19% to ~$0.00288, touching a new all-time low. Exchanges Upbit and Bitget suspend RVN deposits and withdrawals pending chain resolution.

Aug 11: Mining pools 2Miners and RavenMiner (collectively controlling majority hashpower) announce a coordinated chain rollback. 2Miners deploys hotfix v4.6.1.1-hf1 with a checkpoint at block 4,487,775 — rolling back ~3-4 days of transactions on the invalid chain branch. All transactions confirmed after block 4,487,775 are at risk of reversal.

Aug 11+: Core Ravencoin C++ patch to add nHeight validation in KAWPOW headers under development. Media coverage: CoinDesk, Decrypt, crypto.news, Cryptonomist, Web3IsGoingGreat.

As of Aug 20, 2026: Rollback progress and patch deployment status unknown. Attacker not identified. No direct crypto theft — impact is entirely market-based (price drop + chain integrity disruption) and transactional (reversal risk for users who transacted during the invalid chain window).