# form-data: CRLF injection in form-data via unescaped multipart field names and filenames

Advisory record · `GHSA-hmw2-7cc7-3qxx`

- **Identifiers:** `GHSA-hmw2-7cc7-3qxx` · `CVE-2026-12143`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **Critical:** No
- **Weakness (CWE):** [CWE-93](https://cwe.mitre.org/data/definitions/93.html)
- **Tags:** [Other injection](https://agentprime.io/advisories/tag/injection.md)
- **Published:** 15 Jun 2026
- **Updated:** 10 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 15 Jun 2026, 17:26 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `form-data` (npm): affected `<2.5.6 || >=3.0.0, <3.0.5 || >=4.0.0, <4.0.6`; fixed in `2.5.6`, `3.0.5`, `4.0.6`

## 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

- 8.7 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`, from CNA (harborist)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0067, the 52nd percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 12 Jun 2026, 18:00 UTC: [Published by the maintainers as a GitHub repository advisory](https://github.com/form-data/form-data/security/advisories/GHSA-hmw2-7cc7-3qxx)

## Sources

- [GitHub Advisory Database: GHSA-hmw2-7cc7-3qxx](https://github.com/advisories/GHSA-hmw2-7cc7-3qxx)
- [OSV: GHSA-hmw2-7cc7-3qxx](https://osv.dev/vulnerability/GHSA-hmw2-7cc7-3qxx)
- <https://github.com/form-data/form-data/security/advisories/GHSA-hmw2-7cc7-3qxx>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-12143>
- <https://github.com/form-data/form-data/commit/64190db548c0179e37206858e39f27cf513e9435>
- <https://github.com/form-data/form-data/commit/be3f3cf553978bac15a5182f1f3c3d2d38ccf229>
- <https://github.com/form-data/form-data/commit/c7133499c2ee1b80c678e411244f4442bf902045>
- <https://github.com/form-data/form-data>
- <https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#multipart-form-data>
- <https://www.npmjs.com/package/form-data>

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-hmw2-7cc7-3qxx>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-hmw2-7cc7-3qxx/>. Everything for agents: <https://agentprime.io/llms.txt>.