{"id":"CVE-2020-26264","aliases":["EUVD-2021-1389","GHSA-r33q-22hv-j29q","GO-2021-0063"],"status":"published","title":"LES Server DoS via GetProofsV2","description":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. In Geth before version 1.9.25 a denial-of-service vulnerability can make a LES server crash via malicious GetProofsV2 request from a connected LES client. This vulnerability only concerns users explicitly enabling les server; disabling les prevents the exploit. The vulnerability was patched in version 1.9.25.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.01886,"percentile":0.79667,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400"],"published":"2020-12-11T16:45:24Z","modified":"2026-10-20T10:52:56Z","fixes":[{"ecosystem":"Go","package":"github.com/ethereum/go-ethereum","fixed_in":["1.9.25"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/ethereum/go-ethereum","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.9.25"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/ethereum/go-ethereum","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.9.25"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/ethereum/go-ethereum","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.9.25"}]}]}],"products":[{"vendor":"ethereum","product":"go-ethereum"},{"vendor":"ethereum","product":"go_ethereum"}],"references":[{"url":"https://github.com/ethereum/go-ethereum/security/advisories/GHSA-r33q-22hv-j29q","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/ethereum/go-ethereum/pull/21896","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://github.com/ethereum/go-ethereum/commit/bddd103a9f0af27ef533f04e06ea429cf76b6d46","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://github.com/ethereum/go-ethereum/releases/tag/v1.9.25","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-26264","tags":["advisory"]},{"url":"https://pkg.go.dev/vuln/GO-2021-0063","tags":["web"]},{"url":"https://github.com/advisories/GHSA-r33q-22hv-j29q"},{"url":"https://github.com/ethereum/go-ethereum","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2020-26264","title":"LES Server DoS via GetProofsV2","description":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. In Geth before version 1.9.25 a denial-of-service vulnerability can make a LES server crash via malicious GetProofsV2 request from a connected LES client. This vulnerability only concerns users explicitly enabling les server; disabling les prevents the exploit. The vulnerability was patched in version 1.9.25.","status":"published","published":"2020-12-11T16:45:24Z","modified":"2024-08-04T15:56:04.248Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:35:46.129376Z"}],"euvd":[{"id":"EUVD-2021-1389","description":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. In Geth before version 1.9.25 a denial-of-service vulnerability can make a LES server crash via malicious GetProofsV2 request from a connected LES client. This vulnerability only concerns users explicitly enabling les server; disabling les prevents the exploit. The vulnerability was patched in version 1.9.25.","status":"published","published":"2020-12-11T16:45:24Z","modified":"2024-08-04T15:56:04Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T03:07:14.653267Z"}],"ghsa":[{"id":"GHSA-r33q-22hv-j29q","title":"Denial of service in github.com/ethereum/go-ethereum","description":"### Impact\n\nA DoS vulnerability can make a LES server crash via malicious `GetProofsV2` request from a connected LES client.\n\n### Patches\n\nThe vulnerability was patched in https://github.com/ethereum/go-ethereum/pull/21896. \n\n### Workarounds\n\nThis vulnerability only concerns users explicitly enabling `les` server; disabling `les` prevents the exploit. \nIt can also be patched by manually applying the patch in https://github.com/ethereum/go-ethereum/pull/21896. \n\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [go-ethereum](https://github.com/ethereum/go-ethereum)\n* Email us at [security@ethereum.org](mailto:security@ethereum.org)","status":"published","published":"2021-06-29T21:14:07Z","modified":"2023-02-14T21:38:33Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:36:45.67005Z"}],"nvd":[{"id":"CVE-2020-26264","description":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. In Geth before version 1.9.25 a denial-of-service vulnerability can make a LES server crash via malicious GetProofsV2 request from a connected LES client. This vulnerability only concerns users explicitly enabling les server; disabling les prevents the exploit. The vulnerability was patched in version 1.9.25.","status":"published","published":"2020-12-11T17:15:12.793Z","modified":"2026-06-17T03:07:57.273Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium","assessor":"primary"},{"version":"2.0","score":4,"vector":"AV:N/AC:L/Au:S/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:06:27.10541Z"}],"osv":[{"id":"CVE-2020-26264","description":"Go Ethereum, or \"Geth\", is the official Golang implementation of the Ethereum protocol. In Geth before version 1.9.25 a denial-of-service vulnerability can make a LES server crash via malicious GetProofsV2 request from a connected LES client. This vulnerability only concerns users explicitly enabling les server; disabling les prevents the exploit. The vulnerability was patched in version 1.9.25.","status":"published","published":"2020-12-11T17:15:12.793Z","modified":"2026-10-20T10:52:56.303104966Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-02T15:44:16.248747Z"},{"id":"GHSA-r33q-22hv-j29q","title":"Denial of service in github.com/ethereum/go-ethereum","description":"### Impact\n\nA DoS vulnerability can make a LES server crash via malicious `GetProofsV2` request from a connected LES client.\n\n### Patches\n\nThe vulnerability was patched in https://github.com/ethereum/go-ethereum/pull/21896. \n\n### Workarounds\n\nThis vulnerability only concerns users explicitly enabling `les` server; disabling `les` prevents the exploit. \nIt can also be patched by manually applying the patch in https://github.com/ethereum/go-ethereum/pull/21896. \n\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [go-ethereum](https://github.com/ethereum/go-ethereum)\n* Email us at [security@ethereum.org](mailto:security@ethereum.org)","status":"published","published":"2021-06-29T21:14:07Z","modified":"2026-09-10T03:49:26.935137633Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:55.122811Z"},{"id":"GO-2021-0063","title":"Nil pointer dereference via malicious RPC message in github.com/ethereum/go-ethereum","description":"Due to a nil pointer dereference, a maliciously crafted RPC message can cause a panic. If handling RPC messages from untrusted clients, this may be used as a denial of service vector.","status":"published","published":"2021-04-14T20:04:52Z","modified":"2024-05-20T16:03:47Z","updated_at":"2026-11-02T15:47:00.604718Z"}]}}