Prototype Pollution in Lodash
CVE-2026-2950
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: 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: This issue is patched in 4.18.0. Workarounds: None. Upgrade to the patched version.
Vulnerability class: Prototype Pollution
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L.
EPSS exploit prediction
EPSS: 0.004 (29.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001
Affected products
- Lodash — versions 4.17.23, 4.18.0
- Lodash Lodash-Amd — versions 4.17.23, 4.18.0
- Lodash Lodash-Es — versions 4.17.23, 4.18.0
- Lodash Lodash.unset — versions 4.0.0, 4.18.0
Weakness classification (CWE)
References
- ce714d77-add3-4f53-aff5-83d477b104bb (Vendor Advisory)
Frequently asked questions
- What is CVE-2026-2950?
- CVE-2026-2950 is a medium-severity vulnerability in Lodash, classified under Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution). CVSS score: 6.5/10. Published 2026-03-31.
- How severe is CVE-2026-2950?
- Medium severity. CVSS v3 base score is 6.5 out of 10.