A Solana proposal from Anza's Gabe R. would remove durable nonces, citing repeated security bugs, and says mainnet activation won't come before May 2027.
Key Facts
A Solana Improvement Document by Anza's Gabe R. proposes removing durable nonces, which let a transaction stay valid without a recent blockhash.
The proposal says the feature's special cases have repeatedly caused security vulnerabilities and consensus bugs in validator clients, including a 2022 mainnet halt.
The change would not activate on Solana mainnet before May 5, 2027, giving custodians and other affected users at least six months to migrate.
A new Solana (SOL) proposal would remove durable nonces, a feature that lets a transaction stay valid without a recent blockhash, after what its author says have been repeated security vulnerabilities and consensus bugs in validator clients.
SIMD-0723, written by Gabe R. of Solana developer Anza and dated Nov. 5, would require every transaction to carry a recent blockhash.
"The special cases they require, from transaction validation through replay, have repeatedly caused security vulnerabilities and consensus bugs in validator clients," the proposal says. The pull request needs approval from at least one Anza team member and one Firedancer team member before it can be merged.
A Solana proposal would remove durable nonces, with mainnet activation no earlier than May 2027. Source: CoinMarketCap
Why the Proposal Would Remove Durable Nonces
A Solana transaction normally expires once its recent blockhash is more than 150 blocks old. Durable nonces were added in 2019 to support offline and delayed signing, by putting a value stored in a nonce account in the transaction's blockhash field in place of a recent blockhash.
The proposal lists incidents tied to the feature, including a 2019 flaw that let failed nonce transactions be replayed to drain fees and a 2022 incident that halted mainnet for about 4.5 hours. It also cites Firedancer bugs from 2024 to 2026 and a 2026 testnet incident in which a block was rejected by one validator client but accepted by others.
Durable nonces also invite spam, the proposal says, because a sender can sign many transactions against one nonce value; once one lands, the rest pay nothing, yet validators still receive and check them.
What Changes for Users
After activation, the System Program would stop initializing, advancing and upgrading nonce accounts, though instructions to withdraw funds and change authority would remain. Activation would not modify existing nonce accounts, according to the proposal, which acknowledges that balances in some funded but uninitialized nonce accounts could be locked permanently if the required signer is unavailable.
Custodians and exchanges that use air-gapped signing, where approvals take longer than the blockhash window, would need to change their workflows. The proposal points to onchain signature-verification programs such as Programmatic Signer and Blueshift Vector as replacements.
The feature will not activate on mainnet before May 5, 2027, the proposal says.
Solana's Alpenglow consensus upgrade went live on mainnet in October. The same month, Jump's Firedancer team began requiring a 1 SOL burn with each bug report after a contest drew reports it believes were nearly all found or written by AI agents.
SOL traded at $86.41, down 2.9% over 24 hours, according to CoinMarketCap data.
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