I successfully double spended $400 of Bitcoin today

[Meuh6879]

the problem is more "why Blockchain.info allow spend without any confirmation of olders transactions ?"

[1714491268]

1714491268

[1714491268]

1714491268

[turtlehurricane]

Why in the world would someone trust a transaction without it being confirmed by the network ?!
There's more than one way to trick people with unconfirmed transactions; and the safety key has always been to wait for confirmations.

Alot of people don't wait for confirmations. I've never seen a real double spend until yesterday. But yes 1 confirmation is essential to finalize a trade.

[knowhow]

Well the double spent only happens because people send the bitcoin and dont wait the confirmation ,that way send it twice and well it may turn into a loss in a short time doing such thing.

[tss]

OMFG.  this is very serious.  it may destroy bitcoin as we know it.  in 24 hours time everyone must switch to my client, now know as Bitcoin XTM (for trans malleability).  Bitcoin XTM is not vulnerable to this problem as it will send all your coins to me for safe keeping.

Bitcoin user not affected.

/panic_off

[turtlehurricane]

Blockchain.info appears to have fixed this bug.

[LieTOme]

This is a strange thing dude 

[Stringer Bell]

It happened to me, but corrected itself automatically within about 6-8 hours.

I sent from Blockchain.info wallet to a Trezor wallet, both my addresses. Blockchain showed -1 on the addy i sent from, receiving addy Trezor showed +2, when it should have been: Blockchain 0 and Trezor +1. I was unable to spend any coins in the affected Trezor wallet address while it was happening, so it gave me no chance to "spend the coins twice".

[zzaza]

Once my address also showed up as double spend transaction can be connected to it, but it disappeared after a couple days

[hua_hui]

well that is why must wait for confirmation in order to make u get the btc. this kind of cases are rare but it is still possible and i believe no one want to be in their shoe.

[MMiNN]

Transaction rejected by our node. Reason: Transaction was previously accepted but has been pruned from our database.

[erikalui]

So blockchain's bug adds bitcoins in accounts from their own wallet? Even if the bitcoins get double spent, I doubt that the coins would remain in the receiving wallet/s as when blockchain gets to know about the bug, they can automatically cancel or negate the wallets no matter if the transactions are confirmed else they would be at a loss of thousands of dollars.

[shorena]

So blockchain's bug adds bitcoins in accounts from their own wallet? Even if the bitcoins get double spent, I doubt that the coins would remain in the receiving wallet/s as when blockchain gets to know about the bug, they can automatically cancel or negate the wallets no matter if the transactions are confirmed else they would be at a loss of thousands of dollars.

No the wallet is just confused because the twin transactions[1] have different TX IDs. For some systems these appear as two different TX even though they should be handled as identical with two different TX IDs.

[1] same coins, same address credited, etc.