On September 21, 2026, automated collectors took the Flux bridge reserve on Ergo using a mechanism built into the Ergo protocol called storage rent. No private key was compromised and no user funds were lost. Flux is ending the Flux–Ergo bridge, with every snapshot balance honored 1:1 inside Fusion. And because the same mechanism can affect any Ergo token box, Zelcore is changing how it handles every Ergo token, in the release shipping at the end of September.

At a glance

Ergo lets anyone claim a box unmoved for 1,051,200 blocks — about four years — without the owner's private key.
The Flux bridge reserve, held in two boxes since August 2022, was taken on September 21, 2026; Flux reports the operators returned it in full within 24 hours and granted them a 100,000 FLUX bounty.
The Flux–Ergo bridge is ending. FLUX balances as of block 1,878,291 are honored 1:1, claimable inside Fusion from early October.
From the release shipping at the end of September, Zelcore attaches 1 ERG, instead of 0.001 ERG, to every Ergo token transfer.
From the same release, Zelcore checks your Ergo wallets at login and flags any token box at risk, with a one-step "Secure my tokens" fix.
These changes ship end of September, on desktop, mobile and the browser extension.
Zelcore stays on Ergo. Our users' access to their own assets is non-negotiable, on every chain.

What happened to the Flux bridge reserve

Ergo is a UTXO chain: balances live in individual "boxes," each holding an ERG value, optional tokens, and a guarding script. A box that has not moved for 1,051,200 blocks — roughly four years — can be spent by anyone. The guarding script is not evaluated and no private key is needed: the input that spends the claimed box carries an empty spending proof. This has been possible since block 1,051,200 was reached on July 20, 2023.

From there, one of two things happens. If the box holds at least roughly 0.15 ERG, the protocol returns it to the owner's script minus a rent charge of roughly 0.1 ERG per four-year period. If it doesn't, the claimant keeps the entire box — ERG, tokens, NFTs, everything in it. Ordinary wallet software on Ergo, Zelcore included until this release, has routinely attached a default of 0.001 ERG to token transfers, putting every such box on the losing side of that split from the moment it's created. Ergo has never hidden this mechanism — it is documented in the whitepaper and in Ergo's own documentation. This is not a hack. It is Ergo working exactly as designed.

The Flux bridge reserve sat in two boxes created on August 30, 2022, holding 400,000,000 FLUX and 15,000,000 FLUX, each carrying only 0.001 ERG. At 23:00:58 UTC on September 21, 2026, a transaction took the larger box; eighteen minutes later, a second took the remainder. The larger box became claimable at block height 1,878,283 and was claimed ten blocks later, at 1,878,293 — about twenty minutes after eligibility. Flux reports that the operators returned the reserve in full within 24 hours, and it granted them a 100,000 FLUX critical bug bounty for the responsible disclosure and return. The same night, a control case showed the other branch: a 1 ERG bridge box from the same period could pay the rent, so it came back to Flux's own script as 0.90125 ERG, with roughly 0.099 ERG kept as rent.

This isn't isolated. In the 30 days to late September 2026, two collector operations claimed 42,433 boxes from 5,402 addresses. Most could pay and came back minus rent; 6,300 could not and were taken whole — 3,257 of them token boxes, spanning 458 distinct tokens, among them the SigUSD stablecoin, wrapped assets, staking keys and NFTs. In that window the median time from eligibility to claim was about six minutes; in the most recent week observed, every eligible box was claimed within 24 hours. Boxes created between September and December 2022 are reaching their four-year mark now. Flux estimates that, at the observed rate of 1,400 to 1,850 boxes a day, on the order of 130,000 to 170,000 boxes will be claimed across Ergo in the next three months. Drain transactions: bb3607fa… and bafedb4a…. Full write-up: Four Years, Eighteen Minutes: Inside Ergo's Storage-Rent Harvest.

Flux on Ergo ends: claims inside Fusion

The Flux–Ergo bridge is terminated. Flux frames this as consistent with its roadmap of consolidating parallel assets.

The snapshot was taken at Ergo block 1,878,291, at 22:54:55 UTC on September 21, 2026 — two blocks before the drain. Every FLUX balance in that snapshot is honored 1:1, regardless of what happened to the bridge reserve afterward. Per the published snapshot, 483,623.36 FLUX across 2,842 addresses is user-claimable. Check any address at ergo.runonflux.com.

Claims will be made inside Fusion only. The window opens in early October, and a full claim guide will be published before it does. Anything presenting itself as a Flux–Ergo claim portal outside Fusion is a scam. Claims do not depend on the reserve's recovery. Unclaimed Fusion snapshot balances and mining rewards remain claimable on the Flux main chain. FLUX acquired on Ergo after the snapshot carries no claim, so do not buy FLUX on Ergo.

What changes in Zelcore

These changes ship in the Zelcore release at the end of September, on desktop, mobile and the browser extension. Until then, the current release still attaches 0.001 ERG to token sends and has no login check.

1 ERG on every Ergo token transfer. Sending any Ergo token will attach 1 ERG to the recipient's box, not the previous 0.001 ERG — decades of rent coverage instead of a four-year fuse. The 1 ERG goes to the recipient with the token, on every token send. Sending a token needs at least 1 ERG plus the network fee; if the wallet is short, Zelcore says how much ERG is missing. Native ERG sends are unchanged.
A tokens-at-risk check at every login. After you log in, Zelcore will check the Ergo address of each of your wallets that has Ergo activated. If a token box will become claimable within a year, or already is, a dialog titled "Ergo tokens at risk of being taken" will list the wallets, tokens, and estimated dates. It reappears at every login until secured.
Secure my tokens. One action per wallet merges that wallet's under-funded token boxes into a single box carrying at least 1 ERG, sent back to the same wallet. The ERG stays yours — it costs only the network fee. You confirm with an acknowledgement (and d2FA if you have it on); the row shows that it is waiting for the network to confirm. If the wallet holds too little ERG, the dialog says how much to add first.
A plain-words explanation on the send screen for every Ergo asset, linking back to this announcement.
Flux (Ergo) will be marked discontinued in the app, alongside the snapshot notice. Sending FLUX on Ergo remains possible.

Zelcore is staying on Ergo. Our users' access to their own assets is non-negotiable, on every chain.

What to do now

If you use Zelcore: check each of your Ergo addresses at ergo.runonflux.com today — do not wait for the update. When the release arrives at the end of September, update and log in; if the tokens-at-risk dialog appears, use Secure my tokens. Keep at least 1 ERG plus the network fee available in any wallet you use to send Ergo tokens.

If you hold Ergo assets in any wallet: consolidate aging boxes into funded ones, and keep at least 1 ERG on every token box. Treat the four-year mark as a hard deadline — a box older than three years carrying less than roughly 0.15 ERG should be assumed scheduled. Check any address at ergo.runonflux.com; Flux holders should check their snapshot balance there too, and claim inside Fusion from early October.

Our position

Flux has submitted EIP-0049: Prepaid Storage Rent with Archival and Revival, which would drain rent continuously per block and archive exhausted boxes for the owner to revive, removing the confiscation branch entirely. Until that change ships, Flux and Zelcore do not consider Ergo safe for token custody at global scale. That criticism is aimed at a design, not at people, and we thank the Ergo team for working closely with us throughout.