Vulnerability in Zcashfoundation Zebra
CVE-2026-34377
ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.0 and zebra-consensus version 5.0.1, a logic error in Zebra's transaction verification cache could allow a malicious miner to induce a consensus split. By matching a valid transaction's txid while providing invalid authorization data, a miner could cause vulnerable Zebra nodes to accept an invalid block, leading to a consensus split from the rest of the Zcash network. This would not allow invalid transactions to be accepted but could result in a consensus split between vulnerable Zebra nodes and invulnerable Zebra and Zcashd nodes. This issue has been patched in zebrad version 4.3.0 and zebra-consensus version 5.0.1.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H.
EPSS exploit prediction
EPSS: 0.004 (30.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 31st percentile — 30.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Zcashfoundation Zebra — versions < 4.3.0
- Zcashfoundation Zebra-Consensus — versions < 5.0.1
- Zfnd Zebra
- Zfnd Zebra-Consensus
Weakness classification (CWE)
References
- github.com/ZcashFoundation/zebra/security/advisories/GHSA-3vmh-33xr-9cqh (Exploit, Vendor Advisory)
- github.com/ZcashFoundation/zebra/releases/tag/v4.3.0 (Release Notes)
- zfnd.org/zebra-4-3-0-critical-security-fixes-zip-235-support-and-performance-im… (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-34377?
- CVE-2026-34377 is a high-severity vulnerability in Zcashfoundation Zebra, classified under Improper Verification of Cryptographic Signature. CVSS score: 8.1/10. Published 2026-03-31.
- How severe is CVE-2026-34377?
- High severity. CVSS v3 base score is 8.1 out of 10.