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. O3 Security confirms whether GHSA-8cv5-p934-3hwp is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Denial of service in fast-csv
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 | 4.3.6 |
| 📦npm | @fast-csv/parse | all versions | 4.3.6 |
Research 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. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-8cv5-p934-3hwp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-8cv5-p934-3hwp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8cv5-p934-3hwp in your dependencies?
O3 detects GHSA-8cv5-p934-3hwp across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.