GHSA-hrpp-h998-j3pp is a high-severity (CVSS 7.5) CWE-1321 vulnerability in qs. 3 public exploit references exist, so weaponization risk is real. O3 Security confirms whether GHSA-hrpp-h998-j3pp is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
qs vulnerable to Prototype Pollution
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-hrpp-h998-j3pp.
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.
How urgent is this, really
GHSA-hrpp-h998-j3pp plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 368,770 CVEs with a current EPSS score, this one falls in the 10–50% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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.
qsnpmDescription
qs before 6.10.3 allows attackers to cause a Node process hang because an __ proto__ key can be used. In many typical web framework use cases, an unauthenticated remote attacker can place the attack payload in the query string of the URL that is used to visit the application, such as a[__proto__]=b&a[__proto__]&a[length]=100000000. The fix was backported to qs 6.9.7, 6.8.3, 6.7.3, 6.6.1, 6.5.3, 6.4.1, 6.3.3, and 6.2.4.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | qs | ≥ 6.10.0&&< 6.10.3 | 6.10.3 |
| 📦npm | qs | ≥ 6.9.0&&< 6.9.7 | 6.9.7 |
| 📦npm | qs | ≥ 6.8.0&&< 6.8.3 | 6.8.3 |
| 📦npm | qs | ≥ 6.7.0&&< 6.7.3 | 6.7.3 |
| 📦npm | qs | ≥ 6.6.0&&< 6.6.1 | 6.6.1 |
| 📦npm | qs | ≥ 6.5.0&&< 6.5.3 | 6.5.3 |
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 qs. 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 qs to 6.10.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hrpp-h998-j3pp 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-hrpp-h998-j3pp 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-hrpp-h998-j3pp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
- The qs and express Package is not used by the OpenShift Container Platform console directly and is only a third-party package dependency. Hence, it is marked as wontfix. As a result, any services that depend on Openshift for their use of qs and express are marked won't fix. - In OpenShift Service Mesh, 'qs' is…
Frequently Asked Questions
Is GHSA-hrpp-h998-j3pp in your dependencies?
O3 detects GHSA-hrpp-h998-j3pp across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.