CVE-2026-44499

ZEBRA: Permanent Block Discovery Halt via Gossip Queue Saturation and Syncer Poisoning

HIGH
8.7
CVSS Score
Published: May 8, 2026 at 03:11 PM UTC
Updated: October 26, 2026 at 06:10 PM UTC
1 product affected across 1 vendorZebra

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Severity
HIGH8.7
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.4.0
Affected range stops below 4.4.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-770

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