{"id":"CVE-2026-52739","title":"ZEBRA is a Zcash node written entirely in Rust","summary":"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_finali…","severity":"medium","cvss":5.9,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-248"],"vendor":"zebra-state","product":"zebra-state","affected":["zebra-state <= 6.0.0","zebrad <= 4.4.1"],"patched":["zebra-state 7.0.0","zebrad 4.5.0"],"published":"2026-08-18","updated":"2026-09-09","sourceUpdated":"2026-09-09T21:13:25.910","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-52739","references":[{"url":"https://github.com/ZcashFoundation/zebra/commit/1440b43ca7df59aca948090d45117557b217a6cd","label":"security-advisories@github.com"},{"url":"https://github.com/ZcashFoundation/zebra/releases/tag/v4.5.0","label":"security-advisories@github.com"},{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-hhm7-qrv5-h4r6","label":"security-advisories@github.com"},{"url":"https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/Cargo.toml#L304-L305"},{"url":"https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/zebra-consensus/src/transaction.rs#L521-L526"},{"url":"https://github.com/ZcashFoundation/zebra/blob/d4cd662c716382f6397d2a730148025a1ca79fec/zebra-state/src/service/non_finalized_state/chain.rs#L1608-L1628"},{"url":"https://github.com/advisories/GHSA-hhm7-qrv5-h4r6"}],"tags":["nvd","ghsa","rust"],"epss":0.00394,"epssPercentile":0.33406,"ecosystem":"rust","ingestedAt":"2026-07-02T20:42:45.864Z","slug":"CVE-2026-52739","body":"## Overview\n\nZEBRA 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Package advisory (CVE-2026-52739)\n\nAffected packages:\n\n- `zebra-state <= 6.0.0`\n- `zebrad <= 4.4.1`\n\nPatched in:\n\n- `zebra-state 7.0.0`\n- `zebrad 4.5.0`\n\nSource: https://github.com/advisories/GHSA-hhm7-qrv5-h4r6","depth":"sunlit","depthScore":33,"depthScoreParts":{"impact":32.5,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}