{"id":"CVE-2020-26256","aliases":["EUVD-2020-1489","GHSA-8cv5-p934-3hwp"],"status":"published","title":"Denial of service in fast-csv","description":"Fast-csv is an npm package for parsing and formatting CSVs or any other delimited value file in node. In fast-cvs before version 4.3.6 there is a possible ReDoS vulnerability (Regular Expression Denial of Service) when using ignoreEmpty option when parsing. This has been patched in `v4.3.6` You will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6` This vulnerability was found using a CodeQL query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.","severity":{"version":"3.1","score":5.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.01537,"percentile":0.7507,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400"],"published":"2020-12-08T21:42:53Z","modified":"2026-10-20T10:54:20Z","fixes":[{"ecosystem":"npm","package":"fast-csv","fixed_in":["4.3.6"],"sources":["ghsa","osv"]},{"ecosystem":"npm","package":"@fast-csv/parse","fixed_in":["4.3.6"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"fast-csv","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.3.6"}]}]},{"source":"ghsa","ecosystem":"npm","package":"@fast-csv/parse","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.3.6"}]}]},{"source":"osv","ecosystem":"npm","package":"fast-csv","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.3.6"}]}]},{"source":"osv","ecosystem":"npm","package":"@fast-csv/parse","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"4.3.6"}]}]}],"products":[{"vendor":"c2fo","product":"fast-csv"}],"references":[{"url":"https://github.com/C2FO/fast-csv/security/advisories/GHSA-8cv5-p934-3hwp","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://lgtm.com/query/8609731774537641779/","tags":["x_refsource_MISC","x_transferred","Exploit","Third Party Advisory","evidence"]},{"url":"https://github.com/C2FO/fast-csv/issues/540","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/C2FO/fast-csv/commit/4bbd39f26a8cd7382151ab4f5fb102234b2f829e","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://www.npmjs.com/package/%40fast-csv/parse","tags":["x_refsource_MISC","x_transferred","web"]},{"url":"https://www.npmjs.com/package/fast-csv","tags":["x_refsource_MISC","x_transferred","Product","Third Party Advisory","advisory","web"]},{"url":"https://www.npmjs.com/package/@fast-csv/parse","tags":["web"]},{"url":"https://www.npmjs.com/advisories/1587","tags":["web"]},{"url":"https://www.npmjs.com/advisories/1588","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-26256","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-8cv5-p934-3hwp"},{"url":"https://github.com/C2FO/fast-csv","tags":["package"]},{"url":"https://lgtm.com/query/8609731774537641779","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2020-26256","title":"Denial of service in fast-csv","description":"Fast-csv is an npm package for parsing and formatting CSVs or any other delimited value file in node. In fast-cvs before version 4.3.6 there is a possible ReDoS vulnerability (Regular Expression Denial of Service) when using ignoreEmpty option when parsing. This has been patched in `v4.3.6` You will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6` This vulnerability was found using a CodeQL query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.","status":"published","published":"2020-12-08T21:45:19Z","modified":"2024-08-04T15:56:03.099Z","cvss":[{"version":"3.1","score":5.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/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-2020-1489","description":"Fast-csv is an npm package for parsing and formatting CSVs or any other delimited value file in node. In fast-cvs before version 4.3.6 there is a possible ReDoS vulnerability (Regular Expression Denial of Service) when using ignoreEmpty option when parsing. This has been patched in `v4.3.6` You will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6` This vulnerability was found using a CodeQL query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.","status":"published","published":"2020-12-08T21:45:19Z","modified":"2024-08-04T15:56:03Z","cvss":[{"version":"3.1","score":5.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"updated_at":"2026-11-03T03:07:15.778249Z"}],"ghsa":[{"id":"GHSA-8cv5-p934-3hwp","title":"Denial of service in fast-csv","description":"### Impact\nPossible ReDoS (Regular Expression Denial of Service) when using `ignoreEmpty` option when parsing.\n\n### Patches\nThis has been patched in `v4.3.6`\n\n### Workarounds\nYou will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6`\n\n### References\n\nThis vulnerability was found using a [CodeQL](https://securitylab.github.com/tools/codeql) query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.\n[Link to query run](https://lgtm.com/query/8609731774537641779/). \n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [fast-csv](https://github.com/C2FO/fast-csv)","status":"published","published":"2020-12-08T21:42:53Z","modified":"2023-02-01T05:05:04Z","cvss":[{"version":"3.1","score":5.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:36:32.120868Z"}],"nvd":[{"id":"CVE-2020-26256","description":"Fast-csv is an npm package for parsing and formatting CSVs or any other delimited value file in node. In fast-cvs before version 4.3.6 there is a possible ReDoS vulnerability (Regular Expression Denial of Service) when using ignoreEmpty option when parsing. This has been patched in `v4.3.6` You will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6` This vulnerability was found using a CodeQL query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.","status":"published","published":"2020-12-08T22:15:17.54Z","modified":"2026-06-17T03:07:56.073Z","cvss":[{"version":"3.1","score":5.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/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":3.5,"vector":"AV:N/AC:M/Au:S/C:N/I:N/A:P","level":"low","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:06:27.10541Z"}],"osv":[{"id":"CVE-2020-26256","description":"Fast-csv is an npm package for parsing and formatting CSVs or any other delimited value file in node. In fast-cvs before version 4.3.6 there is a possible ReDoS vulnerability (Regular Expression Denial of Service) when using ignoreEmpty option when parsing. This has been patched in `v4.3.6` You will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6` This vulnerability was found using a CodeQL query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.","status":"published","published":"2020-12-08T22:15:17.54Z","modified":"2026-10-20T10:54:20.441598281Z","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":"2026-11-02T15:44:15.879068Z"},{"id":"GHSA-8cv5-p934-3hwp","title":"Denial of service in fast-csv","description":"### Impact\nPossible ReDoS (Regular Expression Denial of Service) when using `ignoreEmpty` option when parsing.\n\n### Patches\nThis has been patched in `v4.3.6`\n\n### Workarounds\nYou will only be affected by this if you use the `ignoreEmpty` parsing option. If you do use this option it is recommended that you upgrade to the latest version `v4.3.6`\n\n### References\n\nThis vulnerability was found using a [CodeQL](https://securitylab.github.com/tools/codeql) query which identified `EMPTY_ROW_REGEXP` regular expression as vulnerable.\n[Link to query run](https://lgtm.com/query/8609731774537641779/). \n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [fast-csv](https://github.com/C2FO/fast-csv)","status":"published","published":"2020-12-08T21:42:53Z","modified":"2026-09-10T03:49:00.474887627Z","cvss":[{"version":"3.1","score":5.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:42.077781Z"}]}}