PT-2026-33597 · Zebra · Zebra

Sangsoo-Osec · Published 2026-04-18 · Updated 2026-04-21 · CVE-2026-40880

Positive Technologies (AI Summary)

CVSS v3.1

8.1

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Zebra versions prior to 4.3.1

Description A logic error in the transaction verification cache allows a malicious miner to induce a consensus split. The issue stems from a performance optimization that skips transaction validation if the transaction was previously accepted into the mempool. This mechanism fails to account for height-dependent validity, such as expiry heights, lock times, or network upgrades. An attacker could submit a transaction valid for height H+1 but invalid for H+2, then mine it into a block at height H+2. Vulnerable nodes may accept the invalid block, leading to a chain fork and network partitioning from the rest of the Zcash network.

Recommendations Update to Zebra version 4.3.1.

Fix

Weakness Enumeration

CWE-1025

Related Identifiers

CVE-2026-40880

GHSA-XVJ8-PH7X-65GF

Affected Products

Zebra

References · 5

• https://github.com/ZcashFoundation/zebra/security/advisories/GHSA-xvj8-ph7x-65gf · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-40880 · Security Note
• https://osv.dev/vulnerability/GHSA-xvj8-ph7x-65gf · Vendor Advisory
• https://github.com/ZcashFoundation/zebra · Note
• https://twitter.com/dailycve/status/2045343017968582828 · Twitter Post