lodash vulnerable to prototype pollution via array-path bypass in `_.unset`, `_.omit`, and `_.pullAt

### Impact The `_.unset`, `_.omit`, and `_.pullAt` functions are vulnerable to prototype pollution. The fix for [CVE-2025-13465](https://github.com/lodash/lodash/security/advisories/GHSA-xxjr-mmjv-4gpg) 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 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. ### Workarounds None. Upgrade to the patched version. ### References - [CVE-2025-13465 / GHSA-xxjr-mmjv-4gpg](https://github.com/lodash/lodash/security/advisories/GHSA-xxjr-mmjv-4gpg) (original fix that this bypasses)

Source published

1 Apr 2026 23:50:27 UTC

Source modified

3 Nov 2026 15:45:08 UTC

Observed here

3 Nov 2026 15:57:27 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

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