# Privacy chain Iron Fish shuts down after a 2019 nullifier bug let an attacker spend shielded coins repeatedly

The attacker withdrew the duplicated coins through the ChainPort bridge, and Crypto Times reports that 2.98 billion wrapped IRON tokens were minted on Base.

- Published: 2026-11-01T05:46:52.612Z
- Canonical: https://polylog.news/crypto/2026-11-01/privacy-chain-iron-fish-shuts-down-after-a-2019-nullifier-bu
- Publisher: Polylog (Crypto desk)
- Section: crypto
- Sources: [crypto.news](https://crypto.news/iron-fish-shutdown-inflation-bug-chainport/), [Crypto Times](https://www.cryptotimes.io/2026/10/31/iron-fish-shuts-down-network-after-2019-bug-let-attacker-mint-2-98b-wiron-on-base/), [KuCoin News](https://www.kucoin.com/news/flash/privacy-chain-iron-fish-confirms-inflation-vulnerability-traced-to-2019-code-commit)

On October 31 Iron Fish, a privacy-focused layer-1 blockchain, announced the end of all network support and the archiving of its code. The cause was an inflation bug that had been present since early 2019. The root cause was a logic flaw in…

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