{"id":"CVE-2026-104423","title":"Zebra (zebrad) before 6.2.1 contains an asymmetric resource consumption vulnerability that allows unauthenticated peers to stall block verification by pushing V6 mempool transactions with invalid Halo2 proofs","summary":"Zebra (zebrad) before 6.2.1 contains an asymmetric resource consumption vulnerability that allows unauthenticated peers to stall block verification by pushing V6 mempool transactions with invalid Halo2 proofs. Attackers can flood the sha…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-405"],"vendor":"ZcashFoundation","product":"zebra","affected":["zebra < 6.2.1"],"published":"2026-10-02","updated":"2026-10-02","sourceUpdated":"2026-10-02T12:17:12.433","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-104423","references":[{"url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-2p4c-3q4q-p463","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/zebra-before-6.2.1-denial-of-service-via-uncapped-v6-shielded-proof-verification","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-10-02T12:17:44.330Z","slug":"CVE-2026-104423","body":"## Overview\n\nZebra (zebrad) before 6.2.1 contains an asymmetric resource consumption vulnerability that allows unauthenticated peers to stall block verification by pushing V6 mempool transactions with invalid Halo2 proofs. Attackers can flood the shared unprioritized Halo2 verification queue with zero-fee transactions carrying zero-filled Orchard and Ironwood proofs, causing nodes to fall behind the chain tip.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}