CVE-2026-44499 — ZEBRA: Permanent Block Discovery Halt via Gossip Queue Saturation and Syncer Poisoning
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…
Published: 2026-05-08 · CVSS: 8.7 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7