CVE-2020-26240 Erroneous Proof of Work calculation in geth

What is CVE-2020-26240?

CVE-2020-26240 is a medium-severity vulnerability in go-ethereum, published on 25 Nov 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Go Ethereum, or "Geth", is the official Golang implementation of the Ethereum protocol. An ethash mining DAG generation flaw in Geth before version 1.9.24 could cause miners to erroneously calculate PoW in an upcoming epoch (estimated early January, 2021). This happened on the ETC chain on 2020-11-06. This issue is relevant only for miners, non-mining nodes are unaffected. This issue is fixed as of 1.9.24

Weakness: CWE-682

Which versions are affected by CVE-2020-26240?

3 open source packages ship an affected version, including github.com/ethereum/go-ethereum. It affects 1 product.

Products include Ethereum Go Ethereum.

How do I fix CVE-2020-26240?

Upgrade github.com/ethereum/go-ethereum to 1.9.24 or later.

Is CVE-2020-26240 being exploited?

There is no known exploitation of CVE-2020-26240 in the wild and no public exploit code.

Other vulnerabilities in go-ethereum

• CVE-2026-26314 Go Ethereum affected by DoS via malicious p2p message High 8.7
• CVE-2023-42319 go-ethereum vulnerable to denial of service via crafted GraphQL query High 7.5
• CVE-2023-40591 Denial of service via malicious p2p message in go-ethereum High 7.5
• CVE-2021-42219 Denial of service in go-ethereum High 7.5
• CVE-2022-23327 Denial of Service in Go-Ethereum High 7.5

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-v592-xf75-856p, GO-2022-0775.