CVE-2026-123556
Published:November 08, 2026
Updated:November 09, 2026
ZcashFoundation Zebra from 4.5.0 before 7.0.0 contains a protection mechanism failure that bans honest peers by scoring mempool lock-time rejections at the ban threshold. Attackers can broadcast transactions locked until the current height right after each block, causing lagging nodes to ban honest relaying peers for 24 hours or until restart.
Affected Packages
https://github.com/ZcashFoundation/zebra.git (GITHUB):
Affected version(s) >=v4.5.0 <v7.0.0 || >=v5.0.0 <v7.0.0 || >=v6.0.0-rc.0 <v7.0.0 || =v7.0.0-rc.0 <v7.0.0Fix Suggestion:
Update to version v7.0.0zebrad (RUST):
Affected version(s) >=6.0.0-rc.0 <7.0.0 || >=5.0.0 <7.0.0 || =7.0.0-rc.0 <7.0.0 || >=4.5.0 <7.0.0Fix Suggestion:
Update to version 7.0.0Related Resources (4)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.9
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Protection Mechanism Failure
EPSS
Base Score:
0.30