CVE-2026-2950

The _.unset and _.omit functions in Lodash are vulnerable to prototype pollution. 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. The issue is patched from 4.18.0 to 4.18.1 depending on the package: lodash, lodash-es, and lodash-amd in 4.18.1, and the standalone lodash.unset and lodash.omit packages in 4.18.0.

Weakness

The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.

Affected Software

Potential Mitigations

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/180.html
• https://cwe.mitre.org/data/definitions/77.html

References

• https://cna.openjsf.org/security-advisories.html
• https://github.com/lodash/lodash/security/advisories/GHSA-f23m-r3pf-42rh