CVE-2020-26240

Name: CVE-2020-26240
Creator: NVD / NIST
Published: 2020-11-25T02:15:10.923+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 1.64%

Last modified Jun 17, 2026

CVE-2020-26240 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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). EPSS estimates a 1.64% chance of exploitation in the next 30 days.

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

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

1.64%

73.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Ethereum	Go Ethereum	< 1.9.24

References

https://blog.ethereum.org/2020/11/12/geth_security_release/Vendor Advisory
https://github.com/ethereum/go-ethereum/commit/d990df909d7839640143344e79356754384dcdd0Patch, Third Party Advisory
https://github.com/ethereum/go-ethereum/pull/21793Patch, Third Party Advisory
https://github.com/ethereum/go-ethereum/security/advisories/GHSA-v592-xf75-856pThird Party Advisory
https://blog.ethereum.org/2020/11/12/geth_security_release/Vendor Advisory
https://github.com/ethereum/go-ethereum/commit/d990df909d7839640143344e79356754384dcdd0Patch, Third Party Advisory
https://github.com/ethereum/go-ethereum/pull/21793Patch, Third Party Advisory
https://github.com/ethereum/go-ethereum/security/advisories/GHSA-v592-xf75-856pThird Party Advisory

Timeline

Published: Nov 25, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-26240?

How severe is CVE-2020-26240?

CVE-2020-26240 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.64% probability of exploitation in the next 30 days.

How do I fix CVE-2020-26240?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-26240?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST