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.

Project Subscriptions

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Advisories
Source ID Title
Github GHSA Github GHSA GHSA-h9hm-m2xj-4rq9 Zebra has Permanent Block Discovery Halt via Gossip Queue Saturation and Syncer Poisoning
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 08 May 2026 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 08 May 2026 16:00:00 +0000

Type Values Removed Values Added
Description 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.
Title ZEBRA: Permanent Block Discovery Halt via Gossip Queue Saturation and Syncer Poisoning
Weaknesses CWE-770
References
Metrics cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-08T17:23:27.910Z

Reserved: 2026-05-06T18:28:20.886Z

Link: CVE-2026-44499

cve-icon Vulnrichment

Updated: 2026-05-08T17:23:24.967Z

cve-icon NVD

Status : Received

Published: 2026-05-08T16:16:13.117

Modified: 2026-05-08T16:16:13.117

Link: CVE-2026-44499

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-08T18:00:16Z

Weaknesses