Is CVE-2026-109366 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-109366?

CVE-2026-109366 has a CVSS v3 severity of LOW (3.7).

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CVE-2026-109366

Description

Zebra before 6.4.0 contains an improper integrity validation vulnerability in the inbound gossip download path that allows unauthenticated peers to force dropping of new blocks without penalty. Attackers can serve a real block with a coinbase scriptSig rewritten to height 1, which keeps the ZIP-244 block hash, triggering a behind-tip drop before consensus validation and delaying tip discovery for mining backends.