Quote from: RoxxR on Today at 10:23:19 PM

Is there a way to use Electrum to double-spend a transaction that is not RBF enabled?
The transaction was made by another wallet that has no RBF support.

I've imported the relevant private key into Electrum and see the pending transaction, but is there a trick for me to cancel it even though I don't have the right-click menu option available due to the absence of the RBF flag?

That's not how transactions works my friend. When you broadcast your transaction to the Bitcoin network, they are propaged to different nodes and that transaction remains there until it's either pick by miners and comfirmed or they purge it later. While transaction remains on their node, you can't double spend the transaction because once they receive the second transaction, they will consider it as double spend unless the node didn't received the first transaction you sent.

If the transaction was first created in electrum, your transaction might not has stuck because by default, your transaction will be flagged as RBF even if you don't set it, electrum wallet do this by default.

Your only way now is CPFP(child pay for parent). If you have access to the private key of wallet address you sent the Bitcoin(receiving wallet address), import the private key on your electrum. You will be paying the fee for the stuck transaction and the new one you are making together.

You need to use high fee sats/vbytes so you don't end up with many uncomfirm transactions, check mempool.space to prioritize your fee.