CVE-2026-109365
Zebra before 6.4.0 Denial of Service via Same-Hash Forged Block Bodies
- State
- Published
- Severity
- 6.3 Medium
- Published
- Oct 12, 2026
- Updated
- Oct 13, 2026
- Reserved
- Oct 12, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.3 Medium | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 3.7 Low | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L | VulnCheck |
Weaknesses
- CWE-345 Insufficient Verification of Data Authenticity
Affected Products
| Product | Versions |
|---|---|
zebraZcashFoundation |
|
References
- GitHub Security Advisory (GHSA-3c94-hf7p-g5mf)vendor-advisory
- VulnCheck Advisory: Zebra before 6.4.0 Denial of Service via Same-Hash Forged Block Bodiesthird-party-advisory
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