Regular Expression Denial of Service in is-my-json-validGHSA-f522-ffg8-j8r6
HIGHFix: github/advisory-database#4850GHSA-f522-ffg8-j8r6 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in is-my-json-valid. A fix is available for is-my-json-valid — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-f522-ffg8-j8r6 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 388,997 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
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.
is-my-json-validnpmDescription
The is-my-json-valid package before 2.12.4 for Node.js has an incorrect exports['utc-millisec'] regular expression, which allows remote attackers to cause a denial of service (blocked event loop) via a crafted string.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | is-my-json-valid | all versions | 2.12.4npm install is-my-json-valid@2.12.4 |
Affected Products
is my json validis_my_json_valid_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for is-my-json-valid, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update is-my-json-valid to 2.12.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f522-ffg8-j8r6 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Frequently Asked Questions
Is GHSA-f522-ffg8-j8r6 in your dependencies?
Find it across npm, including transitive dependencies.