Security readout for executives and security teams
Plain-English summary
This flaw could make older Geth miners calculate Ethereum proof-of-work incorrectly during a future mining epoch. The business risk is mainly failed or invalid mining activity, not compromise of ordinary nodes. Sources state non-mining nodes are unaffected and the issue was fixed in Geth 1.9.24.
Executive priority
Treat this as a targeted mining-infrastructure integrity issue. It is not a general enterprise compromise risk, but unpatched miners could produce invalid work and disrupt revenue or operations. Prioritize only if the organization operated affected Geth mining systems.
Technical view
CVE-2020-26240 is a CWE-682 incorrect calculation flaw in Geth ethash mining DAG generation before 1.9.24. It affects proof-of-work calculation by miners only. CVSS is 5.3 with high attack complexity, no confidentiality impact, and high integrity impact.
Likely exposure
Exposure is limited to organizations running Geth versions earlier than 1.9.24 for mining. Non-mining Geth nodes are out of scope according to the advisory. Historical relevance is strongest for mining operations active around the affected epoch in late 2020 and early 2021.
Exploitation context
The bundle reports this issue occurred on the Ethereum Classic chain on 2020-11-06. It is not listed as KEV, and the supplied sources do not support current active exploitation. Evidence describes a protocol-calculation failure mode for miners, not a broad remote compromise path.
Researcher notes
The key boundary is role-based impact: miners are affected, non-mining nodes are not. Public sources identify the flaw, affected version range, fix version, PR, and commit. They do not provide evidence of KEV listing or current exploitation beyond the reported ETC occurrence.
Mitigation direction
- Upgrade affected Geth miners to version 1.9.24 or later.
- Prioritize mining infrastructure; non-mining nodes are stated unaffected.
- Review the Ethereum release post and GitHub advisory for vendor guidance.
- Pause or isolate mining operations that cannot be version-validated.
Validation and detection
- Inventory all Geth deployments and identify mining roles.
- Confirm miner hosts run Geth 1.9.24 or later.
- Document non-mining Geth nodes as unaffected for this CVE.
- Review mining incident records around 2020-11-06 if Ethereum Classic exposure matters.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CWE-682: Exact CWE lookup
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Open ATT&CK lookupCVE-2020-26240 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N1.63.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.3MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://blog.ethereum.org/2020/11/12/geth_security_release/CVE reference · x_refsource_MISC
- https://github.com/ethereum/go-ethereum/security/advisories/GHSA-v592-xf75-856pCVE reference · x_refsource_CONFIRM
- https://github.com/ethereum/go-ethereum/pull/21793CVE reference · x_refsource_MISC
- https://github.com/ethereum/go-ethereum/commit/d990df909d7839640143344e79356754384dcdd0CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Incorrect Calculation
Incorrect Calculation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.