CVE-2026-73231 is a high-severity (CVSS 7.8) CWE-95 vulnerability in @faker-js/faker. A fix is available for @faker-js/faker — see the affected versions and patch details below.
Faker: helpers.fake exploitable into arbritary code execution
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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-73231.
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
CVE-2026-73231 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 378,567 CVEs with a current EPSS score, this one falls in the < 10% 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.
@faker-js/fakernpmDescription
Summary
faker.helpers.fake can be tricked into arbritary code execution.
Details
fakeEval.resolveProperty resolves properties on functions itself instead of resolving the nested function first. This can be addressed by recursively calling resolveProperty instead of accessing the property after one iteration.
PoC
Go to https://fakerjs.dev/ Open Browser console and run
await enableFaker(); // or import faker
faker.rawDefinitions.test = (() => () => {}); // Any function that returns a function
faker.helpers.fake(`{{test.constructor(alert('PowerLevel: Eval'))}}`);
Impact
The Fake method claims:
It is also NOT possible to use any non-faker methods or plain javascript in such patterns.
Which is objectively false, since any global gets fully accessible in the fake string.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @faker-js/faker | all versions | 10.5.0npm install @faker-js/faker@10.5.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @faker-js/faker, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @faker-js/faker to 10.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-73231 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-73231 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-73231. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-73231 in your dependencies?
O3 Security finds CVE-2026-73231 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.