{"id":"CVE-2020-26241","details":"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.","aliases":["GHSA-69v6-xc2j-r2jf","GO-2022-0771"],"modified":"2026-04-12T00:37:30.502594Z","published":"2020-11-25T02:15:11.047Z","related":["GHSA-69v6-xc2j-r2jf","openSUSE-SU-2025:15424-1"],"references":[{"type":"ADVISORY","url":"https://blog.ethereum.org/2020/11/12/geth_security_release/"},{"type":"ADVISORY","url":"https://github.com/ethereum/go-ethereum/security/advisories/GHSA-69v6-xc2j-r2jf"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/ethereum/go-ethereum","events":[{"introduced":"0"},{"fixed":"748f22c192d24082723f935afd0b0b63e7fd50f4"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.9.17"}],"source":"CPE_FIELD","cpe":"cpe:2.3:a:ethereum:go_ethereum:*:*:*:*:*:*:*:*"}}],"versions":["0.2.2","0.3.0","0.3.1","0.5.13","0.5.14","0.5.15","0.5.16","0.5.17","0.5.18","0.5.19","0.9.16","0.9.23","2","poc1","poc5-rc1","poc5-rc10","poc5-rc11","poc5-rc12","poc5-rc2","poc5-rc3","poc5-rc4","poc5-rc6","poc5-rc7","poc5-rc8","poc5-rc9","v0.8.4","v0.9.17","v0.9.18","v0.9.20","v0.9.21","v0.9.22","v0.9.23","v0.9.24","v0.9.25","v0.9.26","v0.9.28","v0.9.30","v0.9.32","v0.9.34","v0.9.34-1","v0.9.36","v0.9.38","v1.0.1","v1.5.0","v1.5.1","v1.5.2","v1.5.3","v1.5.4","v1.5.5","v1.5.6","v1.5.7","v1.5.8","v1.5.9","v1.6.0","v1.6.1","v1.6.2","v1.6.3","v1.6.4","v1.6.5","v1.6.6","v1.6.7","v1.7.0","v1.7.1","v1.7.2","v1.7.3","v1.8.0","v1.8.1","v1.8.10","v1.8.11","v1.8.12","v1.8.13","v1.8.14","v1.8.15","v1.8.16","v1.8.17","v1.8.18","v1.8.19","v1.8.2","v1.8.20","v1.8.21","v1.8.3","v1.8.4","v1.8.5","v1.8.6","v1.8.7","v1.8.8","v1.8.9","v1.9.0","v1.9.1","v1.9.10","v1.9.11","v1.9.12","v1.9.13","v1.9.14","v1.9.15","v1.9.16","v1.9.2","v1.9.3","v1.9.4","v1.9.5","v1.9.6","v1.9.7","v1.9.8","v1.9.9"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2020-26241.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L"}]}