Out-of-bounds read in go-ethereum - CVE-2020-26242
Published: November 24, 2020 / Updated: April 27, 2026
Vulnerability identifier: #VU127994
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2020-26242
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
go-ethereum
go-ethereum
Software vendor:
Ethereum
Ethereum
Description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an out-of-bounds read in the uint256 library MulMod operation when processing a MULMOD operation with a modulo value of 0. A remote attacker can submit a crafted block containing mulmod(a,b,0) to cause a denial of service.
Successful exploitation causes vulnerable nodes to crash during block processing and drop off the network.
Remediation
Install security update from vendor's website.