CVE-2021-23337: lodash command injection
CVE-2021-23337 (lodash command injection) is a command injection (template) vulnerability in lodash (npm). As of 2026-06-18 it carries an elevated 22.4% probability of exploitation in the next 30 days (EPSS). It is fixed in 4.17.21 — if you depend on an earlier version, upgrade.
| Severity | High |
|---|---|
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H |
| EPSS (exploit probability, 30d) | 22.4% · 97th percentile |
| Vulnerability type | Command Injection (template) |
| Affected package | lodash (npm) |
| Fixed in | 4.17.21 |
What is CVE-2021-23337?
lodash's template function before 4.17.21 allows command injection via a crafted template/options object, letting an attacker run arbitrary code in the Node.js process.
Is CVE-2021-23337 exploitable?
CVE-2021-23337 has an EPSS score of 22.4% (97th percentile), meaning an elevated 22.4% probability of exploitation in the next 30 days. Its CVSS vector is CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H, which scores as High severity. It is a command injection (template) issue.
What is the EPSS score for CVE-2021-23337?
As of 2026-06-18, the EPSS exploit-prediction score for CVE-2021-23337 is 22.4% (97th percentile). EPSS estimates the probability that a vulnerability will be exploited in the wild within the next 30 days and is recomputed daily by FIRST.org.
How do I fix CVE-2021-23337?
Upgrade lodash to 4.17.21 or later. lodash's template function before 4.17.21 allows command injection via a crafted template/options object, letting an attacker run arbitrary code in the Node.js process.
Am I affected by CVE-2021-23337?
You are affected if your project (directly or transitively) depends on a vulnerable version of lodash in the npm ecosystem. Check your lockfile for the resolved version, or scan automatically with VulnFeed.
Check your own project automatically
Don't eyeball every dependency by hand. VulnFeed reads your lockfile, checks it against the same advisory data, and ranks findings by EPSS — free, no signup (10 scans/day):
curl -s https://vulnfeed-api.novadyne.ai/vulnscan/query \
-H 'content-type: application/json' \
-d '{"ecosystem":"npm","package":"PKG","version":"VERSION"}'
Or run it inside Claude Code with no API key — uvx vulnfeed-mcp — and just ask "scan this project for vulnerabilities."
Data sources: vulnerability metadata from OSV.dev and the National Vulnerability Database; exploit-probability (EPSS) from FIRST.org (recomputed daily; EPSS data shown here as of 2026-06-18). Page generated 2026-06-18.