Packages / lodash / Security

ModerateVulnerabilityGHSA-f23m-r3pf-42rhCVE-2026-2950Published 1 Apr 2026

lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`

Your version

Affected releases · lodash

  • 4.x4.0.0 – 4.17.23Fixed in 4.18.0
  • 3.x and older0.1.0 – 3.10.1No fix, no longer updated

On 4.x, the newest line:

npm install lodash@4.18.0
Every release on a timeline
4.x

  1. Affected

    4.0.0 – 4.17.23

    54 releases

  2. Fixed

    4.18.0 – 4.18.1

    2 releases, latest

3.x

  1. Affected

    3.0.0 – 3.10.1

    17 releases

2.x

  1. Affected

    2.0.0 – 2.4.2

    8 releases

1.x

  1. Affected

    1.0.0 – 1.3.1

    9 releases

0.x

  1. Affected

    0.1.0 – 0.10.0

    23 releases

113 stable releases of lodash, oldest to newest, one row per major.

What happens

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.