{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "fixed": "4.5.0"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1440b43ca7df59aca948090d45117557b217a6cd"
            }
          ],
          "repo": "https://github.com/zcashfoundation/zebra",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-hhm7-qrv5-h4r6"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-248"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52739.json",
    "unresolved_ranges": [
      {
        "extracted_events": [
          {
            "fixed": "7.0.0"
          }
        ],
        "source": "AFFECTED_FIELD"
      }
    ]
  },
  "details": "ZEBRA is a Zcash node written entirely in Rust. Prior to 4.5.0, a malicious block producer can terminate zebrad by placing the same shielded transaction in a non-finalized parent block and its child. In zebra-state/src/service/non_finalized_state/chain.rs, Chain::push originally inserted the transaction hash into tx_loc_by_hash and asserted uniqueness before updating shielded data and running the duplicate Sprout, Sapling, or Orchard nullifier checks. The repeated transaction therefore reached the transactions must be unique within a single chain assertion before contextual validation could reject it cleanly. Zebra release builds use panic equals abort, so the reachable assertion terminates the entire process; exploitation requires either two consecutive attacker-mined blocks or an attacker-mined child immediately after an honest block includes the attacker's shielded transaction. This issue is fixed in version 4.5.0.",
  "id": "CVE-2026-52739",
  "modified": "2026-08-21T03:30:24.989909154Z",
  "published": "2026-08-18T19:22:19.865Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52739.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-hhm7-qrv5-h4r6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-52739"
    },
    {
      "type": "FIX",
      "url": "https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ZEBRA: Repeated Non-Finalized Shielded Transaction Aborts Zebra Before Duplicate-Nullifier Rejection"
}