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

{
  "id": "c091bc169bc18f6c869e1a78ae22e4dd22878f335f79b46228bdaf5b81a65696",
  "url": "https://osv.dev/vulnerability/CVE-2026-55764",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Klever-Go: SFT add-quantity `int64` overflow bypasses a finite per-nonce MaxSupply",
    "summary": "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.",
    "evidence": "osv:CVE-2026-55764",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-55764",
      "aliases": [
        "CVE-2026-55764",
        "GHSA-mrpp-v6pg-p54x",
        "GO-2026-6330"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/klever-io/klever-go",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "8bcc600b0ac88070740c63c7ce1c8a968dd85251"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.7.19"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8bcc600b0ac88070740c63c7ce1c8a968dd85251"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8bcc600b0ac88070740c63c7ce1c8a968dd85251"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.7.19"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.7.19"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.7.18",
            "v1.7.17",
            "v1.7.16",
            "v1.7.15",
            "v1.7.14"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55764.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.255614446Z",
      "provider": "osv",
      "references": [
        "https://github.com/klever-io/klever-go/releases/tag/v1.7.19",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55764.json",
        "https://github.com/klever-io/klever-go/security/advisories/GHSA-mrpp-v6pg-p54x",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-55764",
        "https://github.com/klever-io/klever-go/commit/8bcc600b0ac88070740c63c7ce1c8a968dd85251"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-190"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55764.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-55764",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 492946,
  "published_at": "2026-08-28T22:08:27.196+00:00"
}