CVE-2020-26256: c2fo Fast-Csv

Medium severity, CVSS 6.5. EPSS: 1.5% chance of exploitation in the next 30 days.

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.

Affected products

• c2fo Fast-Csv: before 4.3.6 (fixed in 4.3.6)

Published 2020-12-08. Last modified 2026-06-17.