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.
EPSS: 0.003 (16.9th percentile) — read the EPSS interpretation.
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.
Affected products
- Zcashfoundation Zebra — versions < 4.3.0
- Zcashfoundation Zebra-consensus — versions < 5.0.1
- Zfnd Zebra
- Zfnd Zebra-consensus
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, 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.