Buffer overflow in go-ethereum - CVE-2020-26241
Published: November 24, 2020 / Updated: April 27, 2026
Vulnerability identifier: #VU127995
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2020-26241
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Ethereum
Affected software:
go-ethereum
go-ethereum
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a chain split where vulnerable nodes reject the canonical chain.
The vulnerability exists due to memory corruption in the dataCopy precompile when processing crafted contract execution involving RETURNDATACOPY. A remote attacker can deploy a specially crafted contract to cause a chain split where vulnerable nodes reject the canonical chain.
The issue arises because the precompile performs a shallow copy on invocation, which can cause divergent EVM results compared to consensus-compliant nodes.
How to mitigate CVE-2020-26241
Install security update from vendor's website.