# CVE-2026-2950: lodash vulnerable to Prototype Pollution via array path bypass in `_.unset` and `_.omit`

> Attackers can delete properties from built-in prototypes via array path bypass in lodash unset and omit functions.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 31 Mar 2026
- **Updated:** 15 Oct 2026
- **Also known as:** CLEANSTART-2026-WD42763, CLEANSTART-2026-XQ62650, CLSA-2026-1792102343, CLSA-2026-1792327052, CLSA-2026-1792762945, CLSA-2026-1792869761, DEBIAN-CVE-2026-2950, ECHO-447c-1909-d40b, GHSA-f23m-r3pf-42rh, MINI-2hr2-2wwq-rm26, MINI-3mwj-3f63-2hp5, MINI-3q82-mcpx-gwrh, MINI-3wg5-hf3j-vjjg, MINI-3wxc-4cr8-fwg7, MINI-57gf-7j38-qx3c, MINI-57x7-r4vh-5fc2, MINI-65x2-79x6-mfrw, MINI-67fw-588m-rv7h, MINI-6958-7248-rm39, MINI-6wrc-24wr-rg2m, MINI-77f5-gj27-fw42, MINI-8jw4-3pwp-pqvr, MINI-9rv9-2gvf-h2f8, MINI-f8gh-jfjr-4p2f, MINI-fxv3-36q6-vxj5, MINI-g8v6-j2rj-p9wg, MINI-g9j4-5qhf-5mp3, MINI-gc57-j87p-h33w, MINI-h67v-9fvj-jq65, MINI-h684-pcmv-2w5r, MINI-h9mr-22jh-c99c, MINI-hfh8-jg9j-w952, MINI-hqw4-cfwv-whmr, MINI-hrx2-pqc2-p9pm, MINI-j39x-jwr6-w9c2, MINI-jr3f-wfvm-72gq, MINI-p4mf-88q8-c44x, MINI-pvr6-379g-r3jc, MINI-pwv8-jxhq-6gg9, MINI-qh7q-rfff-36wm, MINI-rq9r-rcjj-3546, MINI-vfwp-vv6m-cwmv, MINI-w266-rpff-vrm7, MINI-w76c-4c4m-5m2f, MINI-x28w-fpff-3hx9, ROOT-APP-NPM-CVE-2026-2950, UBUNTU-CVE-2026-2950

## What is CVE-2026-2950?

CVE-2026-2950 is a medium-severity vulnerability in lodash, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### 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.

Weakness: CWE-1321 (Improperly Controlled Modification of Object Prototype Attributes)

## Which versions are affected by CVE-2026-2950?

8 open source packages ship an affected version, including lodash, lodash-amd and lodash-es. It affects 4 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `lodash` | npm | All versions | 4.18.0 |
| `lodash` | npm | All versions | 4.18.0 |
| `lodash-amd` | npm | All versions | 4.18.0 |
| `lodash-amd` | npm | All versions | 4.18.0 |
| `lodash-es` | npm | All versions | 4.18.0 |
| `lodash-es` | npm | All versions | 4.18.0 |
| `lodash.unset` | npm | From 4.0.0 | 4.18.0 |
| `lodash.unset` | npm | From 4.0.0 | 4.18.0 |

Products: Lodash Lodash, Lodash Lodash-Amd, Lodash Lodash-Es, Lodash Lodash.unset.

## How do I fix CVE-2026-2950?

Upgrade lodash to 4.18.0 or later.

## Is CVE-2026-2950 being exploited?

There is no known exploitation of CVE-2026-2950 in the wild and no public exploit code.

## Other vulnerabilities in lodash

- [CVE-2026-4800](https://insights.sbomify.com/CVE-2026-4800/): lodash vulnerable to Code Injection via `_.template` imports key names (high 8.1)
- [CVE-2020-8203](https://insights.sbomify.com/CVE-2020-8203/): Prototype Pollution in lodash (high 7.4)
- [CVE-2021-23337](https://insights.sbomify.com/CVE-2021-23337/): Command Injection (high 7.2)
- [CVE-2025-13465](https://insights.sbomify.com/CVE-2025-13465/): Prototype Pollution Vulnerability in Lodash _.unset and _.omit functions (medium 6.9)
- [CVE-2019-1010266](https://insights.sbomify.com/CVE-2019-1010266/): Regular Expression Denial of Service (ReDoS) in lodash (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-2950 and fix it if it is affected.

What it is: CVE-2026-2950 is a medium-severity vulnerability in lodash, published on 31 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-2950 in the wild and no public exploit code.

Affected packages and fixed versions:
- lodash (npm): affected all versions; fixed in 4.18.0
- lodash (npm): affected all versions; fixed in 4.18.0
- lodash-amd (npm): affected all versions; fixed in 4.18.0
- lodash-amd (npm): affected all versions; fixed in 4.18.0
- lodash-es (npm): affected all versions; fixed in 4.18.0
- lodash-es (npm): affected all versions; fixed in 4.18.0
- lodash.unset (npm): affected from 4.0.0; fixed in 4.18.0
- lodash.unset (npm): affected from 4.0.0; fixed in 4.18.0

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-2950/ (Markdown: https://insights.sbomify.com/CVE-2026-2950/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-2950
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-2950
- OSV: https://osv.dev/vulnerability/CVE-2026-2950

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-2950/
Summaries are generated and may contain mistakes; the official description above is the record.