Low severity · published Oct 12, 2026
CVE-2026-109365
Zebra before 6.4.0 Denial of Service via Same-Hash Forged Block Bodies
3.7
CVSS
0.2%
EPSS
No
On KEV
Description
Zebra before 6.4.0 contains an uncontrolled resource consumption vulnerability that allows unauthenticated peers to force full proof verification by serving forged block bodies with valid header hashes. Attackers can flip authorizing-only bytes such as a coinbase scriptSig, wasting Sapling, Orchard, and Ironwood proof verification without penalty and stalling sync for 67 seconds.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 4% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ZE
zebra · ZcashFoundation
before 6.4.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-109365
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-109365
vendor-advisory
https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-3c94-hf7p-g5mf
third-party-advisory
https://www.vulncheck.com/advisories/zebra-before-6.4.0-denial-of-service-via-same-hash-forged-block-bodies
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