CVE-2021-4300: Halcyon Project Halcyon

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

A vulnerability has been found in ghostlander Halcyon and classified as critical. Affected by this vulnerability is the function CBlock::AddToBlockIndex of the file src/main.cpp of the component Block Verification. The manipulation leads to improper access controls. The attack can be launched remotely. Upgrading to version 1.1.1.0-hal is able to address this issue. The identifier of the patch is 0675b25ae9cc10b5fdc8ea3a32c642979762d45e. It is recommended to upgrade the affected component. The identifier VDB-217417 was assigned to this vulnerability.

Affected products

Published 2023-01-04. Last modified 2026-06-17.