CVE-2026-104421
MEDIUM
NVD
CVSS Score
5.3
Severity
MEDIUM
Published
Oct 02, 2026
Vendor
unknown
Description
Zebra before 6.2.1 contains an incomplete cleanup vulnerability that allows unauthenticated peers to block downloading of valid blocks by leaving rejected hashes in SentHashes. Attackers can send a contextually invalid block sharing an honest block's header hash, causing Request::KnownBlock to skip the honest block and keep nodes behind the tip.