# Prototype Pollution in lodash

Advisory record · `GHSA-p6mc-m468-83gw`

- **Identifiers:** `GHSA-p6mc-m468-83gw` · `CVE-2020-8203`
- **State:** Confirmed
- **Severity:** CVSS 7.4 High
- **Critical:** No
- **Weakness (CWE):** [CWE-770](https://cwe.mitre.org/data/definitions/770.html) · [CWE-1321](https://cwe.mitre.org/data/definitions/1321.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md) · [Prototype pollution](https://agentprime.io/advisories/tag/prototype-pollution.md)
- **Published:** 15 Jul 2020
- **Updated:** 12 Aug 2025
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 15 Jul 2020, 19:15 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `lodash` (npm): affected `>=3.7.0, <4.17.19`; fixed in `4.17.19`
- `lodash-es` (npm): affected `>=3.7.0, <4.17.20`; fixed in `4.17.20`
- `lodash.pick` (npm): affected `>=4.0.0, <=4.4.0`; no fixed version yet
- `lodash.set` (npm): affected `>=3.7.0, <=4.3.2`; no fixed version yet
- `lodash.setwith` (npm): affected `<=4.3.2`; no fixed version yet
- `lodash.update` (npm): affected `<=4.10.2`; no fixed version yet
- `lodash.updatewith` (npm): affected `<=4.10.2`; no fixed version yet
- `lodash-rails` (RubyGems): affected `>=3.7.0, <4.17.19`; fixed in `4.17.19`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.4 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.052, the 92nd percentile, on 9 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 15 Jul 2020, 16:10 UTC: [Confirmed by the CVE List](https://www.cve.org/CVERecord?id=CVE-2020-8203)
- 15 Jul 2020, 17:15 UTC: [Confirmed by NVD](https://nvd.nist.gov/vuln/detail/CVE-2020-8203)

## Sources

- [GitHub Advisory Database: GHSA-p6mc-m468-83gw](https://github.com/advisories/GHSA-p6mc-m468-83gw)
- [OSV: GHSA-p6mc-m468-83gw](https://osv.dev/vulnerability/GHSA-p6mc-m468-83gw)
- <https://nvd.nist.gov/vuln/detail/CVE-2020-8203>
- <https://github.com/lodash/lodash/issues/4744>
- <https://github.com/lodash/lodash/issues/4874>
- <https://github.com/github/advisory-database/pull/2884>
- <https://github.com/lodash/lodash/commit/c84fe82760fb2d3e03a63379b297a1cc1a2fce12>
- <https://hackerone.com/reports/712065>
- <https://hackerone.com/reports/864701>
- <https://github.com/lodash/lodash>
- <https://github.com/lodash/lodash/wiki/Changelog#v41719>
- <https://github.com/rubysec/ruby-advisory-db/blob/master/gems/lodash-rails/CVE-2020-8203.yml>
- <https://security.netapp.com/advisory/ntap-20200724-0006>
- <https://web.archive.org/web/20210914001339/https://github.com/lodash/lodash/issues/4744>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-p6mc-m468-83gw>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

---

The web page: <https://agentprime.io/advisories/GHSA-p6mc-m468-83gw/>. Everything for agents: <https://agentprime.io/llms.txt>.