CVE-2020-26265 Consensus flaw during block processing

What is CVE-2020-26265?

CVE-2020-26265 is a medium-severity vulnerability in go-ethereum, published on 11 Dec 2020. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Go Ethereum, or "Geth", is the official Golang implementation of the Ethereum protocol. In Geth from version 1.9.4 and before version 1.9.20 a consensus-vulnerability could cause a chain split, where vulnerable versions refuse to accept the canonical chain. The fix was included in the Paragade release version 1.9.20. No individual workaround patches have been made -- all users are recommended to upgrade to a newer version.

Weakness: CWE-682

Which versions are affected by CVE-2020-26265?

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-2020-26265?

Upgrade github.com/ethereum/go-ethereum to 1.9.20 or later.

Is CVE-2020-26265 being exploited?

There is no known exploitation of CVE-2020-26265 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-xw37-57qp-9mm4, GO-2021-0105.