Hedera mainnet upgrade to v0.79 (Block Stream / TSS switch)

Hedera moves its mainnet to version 0.79 on November 18, 2026, starting at 18:00 UTC, with about 40 minutes of expected disruption. The release switches on TSS signing for the new Block Stream and concerns the network's native coin, HBAR.

What is happening

According to the network's official status page, the upgrade window runs from 18:00 to roughly 18:40 UTC (19:00 Central European Time). During this time the operators of the consensus nodes install the new software, and users should expect disruption. The notice was published on the evening of November 11.

Version 0.79 is the stage at which the TSS switch takes place. TSS stands for Threshold Signature Scheme: a block counts as signed only once a sufficient majority of nodes has jointly produced a single signature. This feeds the Block Stream, a single verifiable data stream that replaces the Record Stream, the running list of confirmed transactions and their outcomes that services such as block explorers and exchanges currently draw on.

The version first ran on the testnet. A planned testnet upgrade for November 4 was cancelled, then carried out on November 6 at 18:00 UTC and reported complete at 18:07 UTC. Hedera says the HAPI interface, the SDKs, the mirror node explorer, the mirror node REST API and the JSON-RPC relay are not affected. Operators of their own mirror nodes must run at least version 0.163.0, because older versions cannot read the new data stream and will stop receiving data after the switch.

Why it matters

For most HBAR holders the effect is indirect. Transfers, withdrawals or trades on Hedera applications are best planned before the window opens or after it closes. Exchanges can pause Hedera deposits and withdrawals during a network upgrade; whether and for how long is announced on each provider's own status page. If an exchange credits deposits late afterwards, an outdated mirror node on its side may be the cause.

For the project, the release is a technical milestone: nodes sign blocks jointly, and third parties can verify the result without trusting each individual node. By the time of the announcement, detailed release notes for 0.79 had not yet been published in Hedera's documentation. For traders, the main practical point is the short period of reduced availability, which is relevant for anyone holding leveraged positions or time-sensitive transfers.

Key details

• Date: November 18, 2026, 18:00 to about 18:40 UTC (exact time)
• Project: Hedera
• Coins: HBAR
• Category: Mainnet launch
• Status: confirmed
• Source: cryptoticker.io (https://cryptoticker.io/en/hedera-mainnet-upgrade-v0-79-november-18/)