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 key names in options.imports. Only use developer-controlled, static key names.
Impact
Lodash versions 4.0.0 through 4.17.22 are vulnerable to prototype pollution in the .unset and .omit functions. An attacker can pass crafted paths which cause Lodash to delete methods from global prototypes.
The issue permits deletion of properties but does not allow overwriting their original behavior.
Patches
This issue is patched on 4.17.23.
Impact
Lodash versions 4.17.23 and earlier are vulnerable to prototype pollution in the .unset and .omit functions. The fix for CVE-2025-13465 only guards against string key members, so an attacker can bypass the check by passing array-wrapped path segments. This allows deletion of properties from built-in prototypes such as Object.prototype, Number.prototype, and String.prototype.
The issue permits deletion of prototype properties but does not allow overwriting their original behavior.
Patches
This issue is patched in 4.18.0.
Workarounds
None. Upgrade to the patched version.
lodash versions prior to 4.17.21 are vulnerable to Command Injection via the template function.
A flaw was found in nodejs-lodash. A Regular Expression Denial of Service (ReDoS) via the toNumber, trim and trimEnd functions is possible.
A flaw was found in nodejs-lodash in versions 4.17.15 and earlier. A prototype pollution attack is possible which can lead to arbitrary code execution. The primary threat from this vulnerability is to data integrity and system availability.
A prototype pollution vulnerability was found in lodash <4.17.11 where the functions merge, mergeWith, and defaultsDeep can be tricked into adding or modifying properties of Object.prototype.
A Prototype Pollution vulnerability was found in lodash. Calling certain methods with untrusted JSON could lead to modifying objects up the prototype chain, including the global Object. A crafted JSON object passed to a vulnerable method could lead to denial of service or data injection, with various consequences.