What’s Vulnerable › Vulnerabilities

CVE-2026-55764: Klever-Go: SFT add-quantity `int64` overflow bypasses a finite per-nonce MaxSupply

• Severity: high (CVSS 8.7 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-28 · updated 2026-09-09
• Weakness: CWE-190

Description

Klever-Go is the Go implementation of the Klever blockchain protocol. Prior to 1.7.19, Klever-Go allows a mint-role holder to bypass a finite per-nonce MaxSupply on the semi-fungible token add-quantity path. In core/kapp/systemAccount/systemAcount.go, SFTAddCirculation performed meta.Circulation += amount before evaluating whether Circulation exceeded MaxSupply, without checking for signed int64 overflow. A large positive raw Amount supplied through processSemiFungibleAddQuantity in core/kapp/kda/mint.go can wrap Circulation negative, causing the signed maximum-supply comparison to pass and crediting approximately MaxInt64 units while corrupting the on-chain counter. The fungible path is not affected because its MintedValue <= 0 guard detects the overflow. The correction uses the consensus activation flag FixMarketBuyOverflow. This issue is fixed in version 1.7.19.

Affected products

• klever-io klever-go: before 1.7.19

References

• https://github.com/klever-io/klever-go/commit/8bcc600b0ac88070740c63c7ce1c8a968dd85251
• https://github.com/klever-io/klever-go/releases/tag/v1.7.19
• https://github.com/klever-io/klever-go/security/advisories/GHSA-mrpp-v6pg-p54x
• https://github.com/klever-io/klever-go/security/advisories/GHSA-mrpp-v6pg-p54x

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