Denial of service in fast-csv
Impact
Possible ReDoS (Regular Expression Denial of Service) when using ignoreEmpty option when parsing.
Patches
This has been patched in v4.3.6
Workarounds
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
References
This vulnerability was found using a CodeQL query which identified EMPTY_ROW_REGEXP regular expression as vulnerable.
Link to query run.
For more information
If you have any questions or comments about this advisory:
- Open an issue in fast-csv
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | fast-csv | < 4.3.6 | 4.3.6 |
| npm package | @fast-csv/parse | < 4.3.6 | 4.3.6 |
References
- https://github.com/C2FO/fast-csv/security/advisories/GHSA-8cv5-p934-3hwp
- https://nvd.nist.gov/vuln/detail/CVE-2020-26256
- https://github.com/C2FO/fast-csv/issues/540
- https://github.com/C2FO/fast-csv/commit/4bbd39f26a8cd7382151ab4f5fb102234b2f829e
- https://github.com/C2FO/fast-csv
- https://lgtm.com/query/8609731774537641779
- https://www.npmjs.com/advisories/1587
- https://www.npmjs.com/advisories/1588
- https://www.npmjs.com/package/@fast-csv/parse
- https://www.npmjs.com/package/fast-csv
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-400- Platform
- npm
- Package
fast-csv, @fast-csv/parse- Disclosed
- 08.12.2020
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-8cv5-p934-3hwp - CC BY 4.0
Vulnerability history: @fast-csv/parse
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
This is the only known vulnerability of this package.
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