Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M

CVE-2026-40880Zebra: Cached Mempool Verification Bypasses Consensus Rules for Ahead-of-Tip Blocks

High 7.2

In plain English

A high-severity security flaw in zebra-consensus from ZcashFoundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities).

Severity (CVSS 4.0)7.2High

Exploit odds (30 days)0.3%top 82.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

ZEBRA is a Zcash node written entirely in Rust. Prior to zebrad version 4.3.1 and zebra-consensus version 5.0.2, a logic error in Zebra's transaction verification cache could allow a malicious miner to induce a consensus split. By carefully submitting a transaction that is valid for height H+1 but invalid for H+2 and then mining that transaction in a block at height H+2, 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 vulnerability is fixed in zebrad version 4.3.1 and zebra-consensus version 5.0.2.

Affected products (as reported)

Vendor	Product	Versions
ZcashFoundation	zebrad	< 4.3.1
ZcashFoundation	zebra-consensus	< 5.0.2

Weakness: CWE-1025 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H

References

https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf x_refsource_CONFIRM