Hack history / 2026 / Hack or exploit
KiiChain
Hack or exploit on Aug 22, 2026 · Arithmetic Error
IN REVIEWSOURCES AGREE ON DATE AND LOSS · 4 SOURCES
Lost
$9.7M
sources: $9.2M to $9.7M
Returned
none listed
as the sources state it
Rank
#309
among thefts by dollars lost
What happened
An attacker exploited chained balance-accounting defects in the shared Cosmos EVM module used by KiiChain. By deploying a contract at a precomputed vesting-account address and delegating one wei more KII than its spendable balance, the attacker triggered an arithmetic underflow in the staking precompile’s EVM balance write-back. Combined with a missing overflow guard in the EVM value-transfer path, this allowed real KII to be redirected from victim accounts to attacker-controlled addresses without increasing total supply. The sequence was repeated against 18 targets
In review: possible duplicate within one source.
Details
- Date
- Aug 22, 2026
- Kind
- Hack or exploit
- Method
- Arithmetic Error
- How in
- Smart contract bug
- Target
- Chain
- Chains
- KiiChain, Cosmos
Related incidents
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Truebit 2026 · Hack or exploit · $26.4M
Notional V2 2026 · Hack or exploit · $1.7M
TMX TRIBE 2026 · Hack or exploit · $1.4M
Little Boy Plus 2026 · Hack or exploit · $367K
Truebit 2026 · Hack or exploit · $26.4M
Notional V2 2026 · Hack or exploit · $1.7M
TMX TRIBE 2026 · Hack or exploit · $1.4M
Little Boy Plus 2026 · Hack or exploit · $367K
Cite this page
SwanBluechip, "KiiChain hack, Aug 22, 2026: $9.7M lost", Crypto hack history, https://swan-hack-tracker.pages.dev/history/i/ht65ccd97db1/ (data as of 2026-10-31).