GHSA-8cv5-p934-3hwp is a medium-severity (CVSS 5.7) Uncontrolled Resource Consumption vulnerability in fast-csv. 1 public exploit reference exists, so weaponization risk is real. A fix is available for fast-csv — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-8cv5-p934-3hwp by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
fast-csvnpm@fast-csv/parsenpmDescription
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | fast-csv | all versions | 4.3.6npm install fast-csv@4.3.6 |
| 📦npm | @fast-csv/parse | all versions | 4.3.6npm install @fast-csv/parse@4.3.6 |
Affected Products
fast-csvc2foResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for fast-csv, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update fast-csv to 4.3.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8cv5-p934-3hwp is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is GHSA-8cv5-p934-3hwp in your dependencies?
Find it across npm, including transitive dependencies.