Vulnerability · Published Oct 2, 2026 · Assigned by VulnCheck

CVE-2026-104427Zebra before 6.1.0 Chain Stall via Stale parent_error_map Entry

Medium 5.9

In plain English

A medium-severity security flaw in zebra from ZcashFoundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 24% of all known vulnerabilities).

Severity (CVSS 3.1)5.9Medium

Exploit odds (30 days)0.3%top 76.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Zebra before 6.1.0 contains an incomplete cleanup vulnerability in the state write task that allows remote unauthenticated peers to stall node synchronization by poisoning parent_error_map. Attackers can deliver a coinbase-malleated block sharing a canonical block's hash before it propagates, causing the next canonical block to be rejected and stalling the node for roughly 2,000 blocks.

Affected products (as reported)

Vendor	Product	Versions
ZcashFoundation	zebra	0 – before 6.1.0

Weakness: CWE-459 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

References

GitHub Security Advisory (GHSA-8gxx-hc65-vv82) vendor-advisory
VulnCheck Advisory: Zebra before 6.1.0 Chain Stall via Stale parent_error_map Entry third-party-advisory