{"id":"CVE-2026-44499","aliases":["GHSA-h9hm-m2xj-4rq9"],"url":"https://o3.security/vulnerability/CVE-2026-44499","summary":"ZEBRA: Permanent Block Discovery Halt via Gossip Queue Saturation and Syncer Poisoning","details":"ZEBRA is a Zcash node written entirely in Rust. Prior to version 4.4.0, a composite denial-of-service vulnerability in Zebra's block discovery pipeline allows an unauthenticated remote attacker to permanently halt all new block discovery on a targeted node. The attack exploits three independent weaknesses in the gossip, syncer, and download subsystems — all exercisable from a single TCP connection — to create a monotonically growing block deficit that never self-heals. This issue has been patched in version 4.4.0.","published":"2026-05-08T15:11:24.837Z","modified":"2026-08-07T11:31:27.549371876Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"zebrad","fixedVersion":"4.4.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44499.json"},{"type":"ADVISORY","url":"https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-h9hm-m2xj-4rq9"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44499"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:27.549371876Z"}}