CVE-2026-123555
Published:November 08, 2026
Updated:November 09, 2026
Zebra from 2.3.0 before 7.0.0 contains a denial of service vulnerability that allows unauthenticated peers to evade misbehavior scoring by sending transactions or blocks with invalid transparent scripts. Attackers can flood mempool with script-failing transactions or serve forged v5 block bodies with altered scriptSig bytes to exhaust CPU and repeatedly stall block sync.
Affected Packages
https://github.com/ZcashFoundation/zebra.git (GITHUB):
Affected version(s) >=v2.3.0 <v7.0.0 || >=v3.0.0-rc.0 <v7.0.0 || >=v4.0.0 <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 v7.0.0zebra-consensus (RUST):
Affected version(s) >=1.0.0-beta.46 <18.0.0 || >=12.0.0 <18.0.0 || =6.0.0 <18.0.0 || =17.0.0 <18.0.0 || =11.0.0 <18.0.0 || >=3.0.0 <18.0.0 || =7.0.0 <18.0.0 || >=9.0.0 <18.0.0 || =8.0.0 <18.0.0 || >=5.0.0 <18.0.0 || =2.0.0 <18.0.0 || =16.0.0 <18.0.0 || =13.0.0 <18.0.0 || =10.0.0 <18.0.0 || >=14.0.0 <18.0.0 || =4.0.0 <18.0.0 || =15.0.0 <18.0.0Fix Suggestion:
Update to version 18.0.0Related Resources (5)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.7
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
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Improper Handling of Exceptional Conditions
EPSS
Base Score:
0.43