Hack history / 2026 / Hack or exploit
Bisq
Hack or exploit on May 1, 2026 · Missing Input Validation
IN REVIEWSOURCES DISAGREE ON DATE OR LOSS · 2 SOURCES
Lost
$550K
sources: $550K to $876K
Returned
none listed
as the sources state it
Rank
#1,111
among thefts by dollars lost
What happened
Bisq v1 was exploited via missing validation on negative miner fee values in trade protocol. Modified client allowed attacker to pull value from multisig outputs; ~11 BTC stolen from 10 users. Bisq v2 and Easy unaffected.
In review: sources disagree on the loss.
Details
- Date
- May 1, 2026
- Kind
- Hack or exploit
- Method
- Missing Input Validation
- How in
- Smart contract bug
- Target
- DeFi protocol
- Chains
- Bitcoin
After the theft
- Victims reimbursed
- yes, amount not stated
“The team activated emergency measures to disable trading and is preparing a DAO vote for full reimbursement.” (SlowMist Hacked)
Reported by
Related incidents
Cite this page
SwanBluechip, "Bisq hack, May 1, 2026: $550K lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht6276d0a765/ (data as of 2026-10-31).