CVE-2026-104436
Published:October 02, 2026
Updated:October 13, 2026
Zebra before 4.5.0 contains an uncontrolled resource consumption vulnerability that allows remote P2P peers to exhaust blocking-pool threads by sending oversized block locator vectors. Attackers can send getblocks or getheaders messages with up to 65,535 locator hashes, triggering per-hash chain lookups that degrade block validation, RPC, and mempool performance.
Affected Packages
https://github.com/ZcashFoundation/zebra.git (GITHUB):
Affected version(s) >=v4.0.0 <v4.5.0Fix Suggestion:
Update to version v4.5.0zebra-chain (RUST):
Affected version(s) =7.0.0 <8.0.0Fix Suggestion:
Update to version 8.0.0zebrad (RUST):
Affected version(s) >=4.0.0 <4.5.0Fix Suggestion:
Update to version 4.5.0Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
PRESENT
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:
3.7
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
EPSS
Base Score:
0.27