CVE-2026-55763 in Klever-Go
Summary
by MITRE • 08/29/2026
Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.19, processPercentageRoyaltiesTransfer in core/kapp/accounts/accounts.go calls SubFromBalance after the split loop and after the royaltiesToPay <= 0 early return. computeSplitRoyalties rejects only when splitToPay > royaltiesToPay, so a valid PercentTransferPercentage = 10000 split consumes exactly 100 percent of the royalty pool, sets royaltiesToPay to zero, and returns before the source account is debited. The split recipient receives the full royaltyAmount while the sender pays nothing and the supply counter is not updated, allowing unbounded off-the-books inflation of the transferred KDA. A KDA owner must configure a TransferPercentage royalty with a 100 percent split, after which any holder's transfer of the asset triggers the mint; the sibling processFixedRoyaltiesTransfer path is not affected because it debits the source before distribution. This issue is fixed in version 1.7.19.
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Analysis
by VulDB Data Team • 08/29/2026
The vulnerability identified within Klever-Go, specifically prior to version 1.7.19, represents a critical logic flaw in the asset royalty transfer mechanism that enables unbounded inflation of the native KDA cryptocurrency supply. This issue resides in the processPercentageRoyaltiesTransfer function located in core/kapp/accounts/accounts.go and exploits an incorrect sequence of operations during the distribution of royalties on token transfers. The root cause is a failure to properly validate or execute the deduction from the source account before distributing funds, creating a scenario where value can be created ex nihilo without corresponding debits, thereby breaking the fundamental economic integrity of the blockchain ledger.
Technically, the flaw manifests when a KDA asset owner configures a TransferPercentage royalty with a split percentage set to 10000, which corresponds to one hundred percent of the royalties due. When any holder subsequently transfers this specific asset, the smart contract logic enters the processing routine for percentage-based royalties. The code executes a loop to calculate and distribute the specified percentages to designated recipients using SubFromBalance on their respective accounts. However, because the split consumes exactly one hundred percent of the royalty pool, the variable tracking remaining royalties to pay is reduced to zero immediately after this distribution phase. Crucially, due to the flawed control flow, the function returns early before reaching the code block responsible for debiting the source account that initiated the transfer. Consequently, while the recipient accounts receive the full calculated royalty amount in newly minted KDA tokens, the sender's balance remains unchanged and no corresponding deduction occurs on their side of the transaction ledger.
The operational impact of this vulnerability is severe, allowing any user who holds a vulnerable asset to trigger an infinite loop of value creation by repeatedly transferring it. Since each transfer triggers the royalty mechanism without deducting from the sender, users can generate unlimited amounts of KDA tokens out of thin air. This results in unbounded off-the-books inflation that distorts market dynamics and undermines trust in the network's monetary policy. The vulnerability is specific to percentage-based royalties; the sibling processFixedRoyaltiesTransfer path remains unaffected because it correctly debits the source account prior to any distribution, ensuring atomicity between deduction and payment.
This flaw aligns with CWE-390, Detection of Error Condition Without Action, as the system fails to perform a necessary state update (debiting the sender) following an error or completion condition that should have triggered it. It also relates to CWE-841, Improper Enforcement of Behavioral Constraints, because the smart contract logic allows actions that violate the intended economic rules of token transfers and royalty collections. From a threat modeling perspective using MITRE ATT&CK for ICS or general cyber frameworks, this can be categorized under Tactic TA0005: Defense Evasion via Tampering with data integrity, specifically affecting availability and confidentiality through financial manipulation rather than traditional system compromise.
To mitigate this vulnerability, organizations running Klever-Go nodes must upgrade to version 1.7.19 or later immediately. This release corrects the execution order within processPercentageRoyaltiesTransfer to ensure that source account debits occur reliably regardless of split percentages. For environments where upgrading is not instantly feasible, temporary mitigations involve restricting asset transfers for any tokens configured with one hundred percent royalty splits until patches are applied. Additionally, developers should audit other smart contract logic involving financial distributions to ensure that balance modifications are atomic and consistently ordered relative to state updates on all involved accounts.