High 7.5Published Oct 12, 2026

CVE-2026-109363Zebra 6.4.0 before 6.4.2 Denial of Service via Malformed v6 Transaction

Updated under an hour ago (2026-10-19 07:30 UTC)

Does this affect you?

It affects ZcashFoundation zebra. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.43%, higher than 36% of scored CVEs.

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Every CVE for ZcashFoundation zebra

Exploited in the last 30 days

ZcashFoundation Zebra 6.4.0 before 6.4.2 parses version 6 transactions carrying a pre-NU6.3 consensus branch ID, but the size computation during UnminedTx construction treats re-serialization of the Orchard bundle as infallible, so the resulting error trips an expect that aborts zebrad. Unauthenticated peers can send a single pre-handshake tx message to crash the node, and can repeat this after each restart.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-617
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.43% (percentile 36)
Assigned by: VulnCheck
NVD analysis: Deferred
Record last updated: Oct 13, 2026
First seen by InfoSec Signals: Oct 12, 2026

Affected products

Affected products

ZcashFoundation zebra zcashfoundation:zebra (from the name)	from 6.4.0 before 6.4.2; 6.4.2 not affected	CNA record

References

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-h5rr-8pqv-grp9vendor-advisory
https://github.com/ZcashFoundation/zebra/commit/008abac5c99e872f283450d596d95e37851df49apatch
https://www.vulncheck.com/advisories/zebra-6.4.0-before-6.4.2-denial-of-service-via-malformed-v6-transactionthird-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.