Vulnerability · Published Mar 31, 2026 · Assigned by openjs
CVE-2026-2950lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`
Medium 6.5
In plain English
A medium-severity prototype pollution in lodash from lodash. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 27% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-lodash | 4.17.21+dfsg+~cs8.31.198.20210220-9+deb12u1 | DEBIAN-CVE-2026-2950 |
| Debian:13 | node-lodash | 4.17.21+dfsg+~cs8.31.198.20210220-9+deb13u1 | DEBIAN-CVE-2026-2950 |
| Debian:14 | node-lodash | 4.18.1+dfsg-1 | DEBIAN-CVE-2026-2950 |
| Ubuntu:25.10 | node-lodash | 4.17.21+dfsg+~cs8.31.198.20210220-9ubuntu0.25.10.1 | USN-8411-1 |
| Ubuntu:25.10 | node-lodash | 4.17.21+dfsg+~cs8.31.198.20210220-9ubuntu0.25.10.1 | UBUNTU-CVE-2026-2950 |
| Ubuntu:26.10 | node-lodash | no fix listed | UBUNTU-CVE-2026-2950 |
| npm | lodash | 4.18.1 | GHSA-f23m-r3pf-42rh |
| npm | lodash-amd | 4.18.1 | GHSA-f23m-r3pf-42rh |
| npm | lodash-es | 4.18.1 | GHSA-f23m-r3pf-42rh |
| npm | lodash.omit | 4.18.0 | GHSA-f23m-r3pf-42rh |
| npm | lodash.unset | 4.18.0 | GHSA-f23m-r3pf-42rh |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| lodash | lodash | 4.17.23 – before 4.18.1 |
| lodash | lodash-es | 4.17.23 – before 4.18.1 |
| lodash | lodash-amd | 4.17.23 – before 4.18.1 |
| lodash | lodash.unset | 0 – before 4.18.0 |
| lodash | lodash.omit | 0 – before 4.18.0 |
Weakness: CWE-1321 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L