CVE-2026-109366

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.

CVSS v3 3.7 LOW

3.7^/10

CVSS v3 : LOW

Vector :

Exploitability : 2.2 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
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

Configurations

No configuration.

History

26 Oct 2026, 21:17

Type	Values Removed	Values Added
References	~~() https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4f6v-mj46-gxg3 -~~	() https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-4f6v-mj46-gxg3 -

12 Oct 2026, 17:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-12 17:17

Updated : 2026-10-26 21:17

NVD link : CVE-2026-109366

Mitre link : CVE-2026-109366

CVE.ORG link : CVE-2026-109366

JSON object : View

Products Affected

No product.

CWE

CWE-354

Improper Validation of Integrity Check Value

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