GHSA-9hq5-pfgc-cx5h: Zebra before 7.0.0 Sync Denial of Service via Forged Checkpoint Block Body

Published Nov 8, 2026

Updated

Zebra before 7.0.0 contains an incomplete cleanup vulnerability that allows unauthenticated peers to stall initial sync by serving a forged checkpoint block body. Attackers can supply a body with forged authorizing data near the final checkpoint, leaving rejected hashes in the sent-hash set so the node stops requesting blocks until restart.

Event History

Nov 8, 2026

CVE Published

via OSV·01:38 AM

Data Sourced

via OSV·01:38 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Which nodes are exposed to this denial of service?

Zebra nodes running a version before 7.0.0 are exposed during initial synchronization. The affected condition involves checkpoint blocks near the final checkpoint.

What must an attacker do to trigger the issue?

An unauthenticated peer must serve a forged checkpoint block body containing forged authorizing data near the final checkpoint. This can leave rejected hashes in the sent-hash set and prevent further block requests.

What happens after exploitation, and is a restart a recovery option?

The node can stop requesting blocks, stalling initial sync. Restarting the node restores its ability to request blocks, according to the described behavior.

GHSA-9hq5-pfgc-cx5h: Zebra before 7.0.0 Sync Denial of Service via Forged Checkpoint Block Body

Event History

Frequently Asked Questions

Which nodes are exposed to this denial of service?

What must an attacker do to trigger the issue?

What happens after exploitation, and is a restart a recovery option?

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Frequently Asked Questions

Which nodes are exposed to this denial of service?

What must an attacker do to trigger the issue?

What happens after exploitation, and is a restart a recovery option?