How severe is GHSA-5gc4-cx9x-9c43?

GHSA-5gc4-cx9x-9c43 has a CVSS score of 9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-5gc4-cx9x-9c43?

GHSA-5gc4-cx9x-9c43 affects the following packages: metacalc (npm). Ecosystems affected: npm.

How do I fix GHSA-5gc4-cx9x-9c43?

Update metacalc to 0.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5gc4-cx9x-9c43 is resolved across your whole dependency graph.

How do I detect GHSA-5gc4-cx9x-9c43 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for metacalc. 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.

How do I mitigate GHSA-5gc4-cx9x-9c43 if there is no patch (or I can't update yet)?

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 does O3 Security protect against GHSA-5gc4-cx9x-9c43?

O3 pinpoints whether GHSA-5gc4-cx9x-9c43 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is GHSA-5gc4-cx9x-9c43 actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-5gc4-cx9x-9c43, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for GHSA-5gc4-cx9x-9c43?

GHSA-5gc4-cx9x-9c43 has an EPSS (Exploit Prediction Scoring System) score of 2.4%, placing it in the 82th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-5gc4-cx9x-9c43?

GHSA-5gc4-cx9x-9c43 is classified as Code Injection (CWE-94). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-5gc4-cx9x-9c43 published, and has it been updated?

GHSA-5gc4-cx9x-9c43 was published on June 9, 2022 and was last updated on March 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-5gc4-cx9x-9c43

CRITICAL

Code Injection in metacalc

Also known asCVE-2022-21122

Published

Jun 9, 2022

Updated

Mar 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

2.4%probability of exploitation in next 30 days

Lower Risk82th percentile+1.29%

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

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

metacalcnpm

23downloads / week

Description

The package metacalc before 0.0.2 is vulnerable to Arbitrary Code Execution when it exposes JavaScript's Math class to the v8 context. As the Math class is exposed to user-land, it can be used to get access to JavaScript's Function constructor.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`metacalc`	all versions	0.0.2

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

The package metacalc before 0.0.2 are vulnerable to Arbitrary Code Execu…

snyk.ioNVDJun 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for metacalc. 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 metacalc to 0.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-5gc4-cx9x-9c43 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-5gc4-cx9x-9c43 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-5gc4-cx9x-9c43. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is GHSA-5gc4-cx9x-9c43 in your dependencies?

O3 detects GHSA-5gc4-cx9x-9c43 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works