THORChain has paused native Zcash swaps after a bug deducted RUNE from the bonds of 18 node operators. The protocol says no user or vault funds were lost, and a fix is expected in the v3.21 upgrade around October 23, 2026.
THORChain has paused native Zcash (ZEC) swaps after a bug cut into the bonds of its node operators. Onchain records show about 140 RUNE deducted from 18 node accounts.
The protocol says no user or vault funds were lost. The losses fell on the operators who run the network.
An outbound matching bug triggers a slash
The problem traces back to how THORChain matches outbound ZEC transactions, the step where the protocol sends coins out of its vaults to a user once a swap settles. The network treated a failure in that process as a vault slash and penalized the nodes responsible.
Onchain, the incident occurred around October 19, 2026. The penalty came out of each operator's bond, the RUNE that node operators lock up as collateral for running the network.
v3.21 upgrade is the expected fix
ZEC swaps stay frozen until the v3.21 network upgrade arrives. The upgrade is expected around block height ~28,366,100, which lands on October 23, 2026.
Native ZEC support is new. The liquidity pool launched on October 2, 2026, and a soft launch brought full swap functionality online by October 7-8, 2026.
A second report from Crypto Briefing says the same upgrade targets a separate problem. An exploit detected on September 26 allowed unauthorized transfers of a concentrated liquidity position in the Rujira FIN contract, and the App Layer was paused on September 27, 2026. If node operators approve, v3.21 also restores support for SOL and ZEC trading, limit swaps and bRUNE staking.
Second disruption in October
The ZEC halt is not THORChain's only incident this month. On October 9, Tether temporarily blacklisted approximately 1.45 million USDT across four of THORChain's TRON vaults.
That freeze disrupted related swaps and liquidity provision actions for around three hours. The two incidents had different causes: an outside issuer froze funds in the Tether case, while the ZEC problem came from THORChain's own code.
Next, the source points to whether v3.21 ships on schedule, whether ZEC swaps return without further slashes, and whether THORChain explains what went wrong in outbound matching.
Sources: Crypto Briefing, Crypto Briefing
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