{"api_version":"1","generated_at":"2026-04-09T23:58:50+00:00","cve":"CVE-2020-26241","urls":{"html":"https://cve.report/CVE-2020-26241","api":"https://cve.report/api/cve/CVE-2020-26241.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2020-26241","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2020-26241"},"summary":{"title":"CVE-2020-26241","description":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. This is a Consensus vulnerability in Geth before version 1.9.17 which can be used to cause a chain-split where vulnerable nodes reject the canonical chain. Geth's pre-compiled dataCopy (at 0x00...04) contract did a shallow copy on invocation. An attacker could deploy a contract that writes X to an EVM memory region R, then calls 0x00..04 with R as an argument, then overwrites R to Y, and finally invokes the RETURNDATACOPY opcode. When this contract is invoked, a consensus-compliant node would push X on the EVM stack, whereas Geth would push Y. This is fixed in version 1.9.17.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2020-11-25 02:15:00","updated_at":"2020-12-03 15:48:00"},"problem_types":["CWE-682"],"metrics":[],"references":[{"url":"https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf","name":"https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf","refsource":"CONFIRM","tags":["Third Party Advisory"],"title":"Shallow copy in the 0x4 precompile could lead to EVM memory corruption · Advisory · ethereum/go-ethereum · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"0"},{"url":"https://blog.ethereum.org/2020/11/12/geth_security_release/","name":"https://blog.ethereum.org/2020/11/12/geth_security_release/","refsource":"MISC","tags":["Vendor Advisory"],"title":"Geth security release | Ethereum Foundation Blog","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://www.cve.org/CVERecord?id=CVE-2020-26241","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-26241","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2020","cve_id":"26241","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"ethereum","cpe5":"go_ethereum","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2020","cve_id":"26241","vulnerable":"1","versionEndIncluding":"1","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"ethereum","cpe5":"go_ethereum","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[{"cve":"CVE-2020-26241","qid":"982039","title":"Go (go) Security Update for github.com/ethereum/go-ethereum/core/vm (GHSA-69v6-xc2j-r2jf)"}]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2020-26241","STATE":"PUBLIC","TITLE":"Shallow copy bug in geth"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"go-ethereum","version":{"version_data":[{"version_value":">= 1.9.7, < 1.9.17"}]}}]},"vendor_name":"ethereum"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. This is a Consensus vulnerability in Geth before version 1.9.17 which can be used to cause a chain-split where vulnerable nodes reject the canonical chain. Geth's pre-compiled dataCopy (at 0x00...04) contract did a shallow copy on invocation. An attacker could deploy a contract that writes X to an EVM memory region R, then calls 0x00..04 with R as an argument, then overwrites R to Y, and finally invokes the RETURNDATACOPY opcode. When this contract is invoked, a consensus-compliant node would push X on the EVM stack, whereas Geth would push Y. This is fixed in version 1.9.17."}]},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-682: Incorrect Calculation"}]}]},"references":{"reference_data":[{"name":"https://blog.ethereum.org/2020/11/12/geth_security_release/","refsource":"MISC","url":"https://blog.ethereum.org/2020/11/12/geth_security_release/"},{"name":"https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf","refsource":"CONFIRM","url":"https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf"}]},"source":{"advisory":"GHSA-69v6-xc2j-r2jf","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2020-11-25 02:15:00","lastModifiedDate":"2020-12-03 15:48:00","problem_types":["CWE-682"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"LOW","baseScore":7.1,"baseSeverity":"HIGH"},"exploitabilityScore":2.8,"impactScore":4.2},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:S/C:N/I:P/A:P","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"SINGLE","confidentialityImpact":"NONE","integrityImpact":"PARTIAL","availabilityImpact":"PARTIAL","baseScore":5.5},"severity":"MEDIUM","exploitabilityScore":8,"impactScore":4.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:ethereum:go_ethereum:*:*:*:*:*:*:*:*","versionEndExcluding":"1.9.17","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2020","CveId":"26241","Ordinal":"187663","Title":"CVE-2020-26241","CVE":"CVE-2020-26241","Year":"2020"},"notes":[{"CveYear":"2020","CveId":"26241","Ordinal":"1","NoteData":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. This is a Consensus vulnerability in Geth before version 1.9.17 which can be used to cause a chain-split where vulnerable nodes reject the canonical chain. Geth's pre-compiled dataCopy (at 0x00...04) contract did a shallow copy on invocation. An attacker could deploy a contract that writes X to an EVM memory region R, then calls 0x00..04 with R as an argument, then overwrites R to Y, and finally invokes the RETURNDATACOPY opcode. When this contract is invoked, a consensus-compliant node would push X on the EVM stack, whereas Geth would push Y. This is fixed in version 1.9.17.","Type":"Description","Title":null},{"CveYear":"2020","CveId":"26241","Ordinal":"2","NoteData":"2020-11-24","Type":"Other","Title":"Published"},{"CveYear":"2020","CveId":"26241","Ordinal":"3","NoteData":"2020-11-24","Type":"Other","Title":"Modified"}]}}}