CVE-2026-104431
Published:October 02, 2026
Updated:October 10, 2026
Zebra before 6.0.0 contains a denial of service vulnerability that allows unauthenticated peers to stall Tokio workers by submitting mempool transactions requiring expensive synchronous script verification. Attackers can send non-standard high-sigop P2SH transactions that reach CachedFfiTransaction::is_valid() before standardness checks, saturating the verifier buffer and rendering the node unresponsive.
Affected Packages
https://github.com/ZcashFoundation/zebra.git (GITHUB):
Affected version(s) =v6.0.0-rc.0 <v6.0.0Fix Suggestion:
Update to version v6.0.0zebra-consensus (RUST):
Affected version(s) =10.0.0 <11.0.0Fix Suggestion:
Update to version 11.0.0zebrad (RUST):
Affected version(s) =6.0.0-rc.0 <6.0.0Fix Suggestion:
Update to version 6.0.0Related Resources (4)
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)
Asymmetric Resource Consumption (Amplification)
EPSS
Base Score:
0.34