CVE-2026-109366

CVSS 6.3 (medium) · published 2026-10-12

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.

Weakness: CWE-354

Source: NVD CVE-2026-109366

References

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4f6v-mj46-gxg3
• https://www.vulncheck.com/advisories/zebra-before-6.4.0-gossiped-block-drop-via-forged-coinbase-scriptsig-height
• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4f6v-mj46-gxg3

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