Quote from: Jan on February 11, 2014, 11:21:50 AM

Quote from: nibyokwy on February 11, 2014, 08:44:27 AM

Quote from: Jan on February 11, 2014, 07:33:15 AM

Two transactions with different hashes and with overlapping inputs.
The definition is not entirely correct as a malled tx is not a double spend.

it will result in one though if the user has also tried to spend the change output of the original transaction that was voided by the malleable one. this seems to be happening quite a lot based on network chatter. probably because the client allows spending the change while it's unconfirmed.

Correct. All wallets allowing spending unconfirmed coins-sent-to-self (bitcoin-qt included) are potentially affected.
If this trend continues wallets may have to abandon this practice until mallability issues have been resolved.

I had a similar issue about one year ago. I was using bitcoind offline to issue several transactions, and probably some were taking change from the previous ones.

Afterwards, I took all the generated txs with getrawtransaction and went broadcast them through a connected computer on blockchain.info/pushtx.

I then saw that some were refused due to already spent outpoints, and I think it might be the very problem you are talking about.

But as long as there is no real attack, just rescanning to reference the mutated txid for subsequent spendings should be sufficient right?