CVE-2026-104421

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 sk...

CVE-2026-104421 Zebra before 6.2.1 Block Download Denial of Service via KnownBlock SentHashes Lockout

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 sk...

EUVD-2026-91432

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 sk...

CVE-2026-104421

Zebra versions before 6.2.1 are vulnerable to an incomplete cleanup vulnerability (CWE-459). This flaw allows unauthenticated peers to prevent the downloading of valid blocks by leaving rejected hashes in SentHashes . An attacker can transmit a contextually invalid block that shares an honest blo...