High, CVSS 8.1npmAmendedPublished
lodash vulnerable to Code Injection via _.template imports key names
CVE-2026-4800 · GHSA-r5fr-rjxr-66jc
- Affected
- npm lodash.template >= 4.0.0, < 4.18.0
- Fixed in
- 4.18.0· Vendor fix available
- Issue
- Impact The fix for CVE-2021-23337 added validation for the variable option in .template but did not apply the same validation to options.imports key names. Both paths flow into the same Function() constructor sink. When an application passes untrusted input as options.imports key names, an attacker can inject default-parameter expressions that execute arbitrary code at template compilation time. Additionally, .template uses assignInWith to merge imports, which enumerates inherited properties via for..in. If Object.prototype has been polluted by any other vector, the polluted keys are copied into the imports object and passed to Function(). Patches Users should upgrade to version 4.18.0. The fix applies two changes: 1. Validate importsKeys against the existing reForbiddenIdentifierChars regex (same check already used for the variable option) 2. Replace assignInWith with assignWith when merging imports, so only own properties are enumerated Workarounds Do not pass untrusted input as…
Recommended action: Upgrade to 4.18.0 or later, then redeploy and verify.A vendor fix does not resolve your finding until you verify it in your own systems.