CVE-2026-34377

high

Description

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.

References

https://zfnd.org/zebra-4-3-0-critical-security-fixes-zip-235-support-and-performance-improvements

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-3vmh-33xr-9cqh

https://github.com/ZcashFoundation/zebra/releases/tag/v4.3.0

Details

Source: Mitre, NVD

Published: 2026-03-31

Updated: 2026-04-01

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:P

Severity: Medium

CVSS v3

Base Score: 9.1

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Severity: Critical

CVSS v4

Base Score: 8.4

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H

Severity: High

EPSS

EPSS: 0.00025