VulnerabilityAnalyzed

CVE-2026-34377

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.

HIGH 8.4EPSS 0.26%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.26%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 4.0: 8.4 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS: 0.26% probability · 17th percentile
CISA KEV: Not listed
Weakness: CWE-347
Affected: zfnd/zebra · zfnd/zebra-consensus
Source: security-advisories@github.com

References

https://github.com/ZcashFoundation/zebra/releases/tag/v4.3.0Release Notes
https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-3vmh-33xr-9cqhExploit, Vendor Advisory
https://zfnd.org/zebra-4-3-0-critical-security-fixes-zip-235-support-and-performance-improvementsVendor Advisory

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.