GHSA-mpg4-rc92-vx8v
HIGHfast-xml-parser vulnerable to ReDOS at currency parsing
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
fast-xml-parsernpmDescription
Summary
A ReDOS that exists on currency.js was discovered by Gauss Security Labs R&D team.
Details
https://github.com/NaturalIntelligence/fast-xml-parser/blob/v4.4.0/src/v5/valueParsers/currency.js#L10 contains a vulnerable regex
PoC
pass the following string '\t'.repeat(13337) + '.'
Impact
Denial of service during currency parsing in experimental version 5 of fast-xml-parser-library
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | fast-xml-parser | ≥ 4.3.5&&< 4.4.1 | 4.4.1 |
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-xml-parser. 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-xml-parser to 4.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mpg4-rc92-vx8v 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-mpg4-rc92-vx8v 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-mpg4-rc92-vx8v. 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-mpg4-rc92-vx8v in your dependencies?
O3 detects GHSA-mpg4-rc92-vx8v across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.