Security readout for executives and security teams
Plain-English summary
Geth versions 1.9.7 through before 1.9.17 could disagree with other Ethereum clients about valid chain state. A malicious smart contract could trigger a consensus mismatch, causing vulnerable nodes to reject the canonical chain. For organizations relying on affected Geth nodes, the business risk is incorrect chain view and service disruption, not data theft.
Executive priority
Treat this as a targeted infrastructure integrity issue. It is not marked as exploited, but affected Geth nodes could follow the wrong chain view. Upgrade or verify versions promptly where Ethereum node correctness supports revenue, custody, trading, compliance, or customer-facing services.
Technical view
CVE-2020-26241 is a CWE-682 consensus flaw in go-ethereum. The dataCopy precompile performed a shallow copy, so Geth could place different data on the EVM stack than consensus-compliant nodes after return-data copying. Affected versions are >=1.9.7 and <1.9.17; fixed in 1.9.17.
Likely exposure
Exposure is limited to Ethereum infrastructure running Geth versions >=1.9.7 and <1.9.17. Nodes upgraded to 1.9.17 or later are not described as affected. The bundle does not name other clients, forks, managed services, or hosted node providers as affected.
Exploitation context
The sources describe a feasible network-reachable, low-complexity consensus attack requiring privileges to deploy or invoke a malicious contract. KEV is false, and the provided sources do not state active exploitation. The impact is integrity of chain consensus, not confidentiality or direct availability loss.
Researcher notes
The key exposure condition is running vulnerable go-ethereum versions. The bug is consensus-relevant because Geth could produce different EVM stack data than compliant nodes. Evidence supports the version range and fixed release, but not active exploitation, affected managed providers, or non-Geth products.
Mitigation direction
- Upgrade go-ethereum Geth to version 1.9.17 or later.
- Identify and retire any remaining Geth versions from 1.9.7 through 1.9.16.
- Review Ethereum Foundation and go-ethereum advisory guidance before operating exposed nodes.
- Prioritize externally connected validators, archive nodes, RPC backends, and transaction-processing infrastructure.
Validation and detection
- Inventory all Ethereum nodes and record their exact Geth versions.
- Confirm no production node reports Geth 1.9.7 through 1.9.16.
- Check deployment images, automation, and rollback versions for vulnerable Geth builds.
- Verify monitoring would detect peers rejecting the canonical chain unexpectedly.
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-2020-26241 mapping review
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Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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:L/PR:L/UI:N/S:U/C:N/I:H/A:N2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/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-69v6-xc2j-r2jfCVE reference · x_refsource_CONFIRM
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.