Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount

{
  "id": "5345ca94a0a7566ddda7e09584a4af0f8999d78cf0ed6ee3d5ef9333fabdd8fd",
  "url": "https://osv.dev/vulnerability/CVE-2026-104430",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Zebra 4.5.0 Consensus Split via P2SH Sigop Overcount",
    "summary": "Zebra zebrad 4.5.0 and zebra-script 7.0.0 count P2SH redeem script signature operations in legacy mode rather than zcashd's accurate P2SH mode, overcounting CHECKMULTISIG preceded by OP_1 through OP_16 as 20 sigops and causing a consensus divergence. Remote attackers can broadcast P2SH spends using low-threshold multisig redeem scripts so that a block zcashd accepts exceeds Zebra's inflated MAX_BLOCK_SIGOPS count, causing Zebra nodes to reject it and stall off the chain.",
    "evidence": "osv:CVE-2026-104430",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-104430",
      "aliases": [
        "CVE-2026-104430",
        "GHSA-2prc-cj5x-4443"
      ],
      "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/zcashfoundation/zebra",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1440b43ca7df59aca948090d45117557b217a6cd"
                },
                {
                  "fixed": "76c440e67f2c909cbf8418b11a3f56371aed7d95"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "4.5.0"
                      },
                      {
                        "fixed": "4.5.1"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v4.5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-104430.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.727975998Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104430.json",
        "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-2prc-cj5x-4443",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-104430",
        "https://www.vulncheck.com/advisories/zebra-4.5.0-consensus-split-via-p2sh-sigop-overcount"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-628"
        ],
        "cna_assigner": "VulnCheck",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "7.0.0"
                  },
                  {
                    "fixed": "7.0.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/104xxx/CVE-2026-104430.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-104430",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499974,
  "published_at": "2026-10-02T11:38:09.916+00:00"
}