# CVE-2022-35948: CRLF Injection in Nodejs ‘undici’ via Content-Type

> Attackers can inject CRLF sequences into HTTP headers via unsanitized content-type input, causing request splitting in the undici library.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Aug 2022
- **Updated:** 22 Apr 2025
- **Also known as:** DEBIAN-CVE-2022-35948, GHSA-f772-66g8-q5h3

## What is CVE-2022-35948?

CVE-2022-35948 is a medium-severity vulnerability in Nodejs Undici, published on 13 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

undici is an HTTP/1.1 client, written from scratch for Node.js.`=< undici@5.8.0` users are vulnerable to _CRLF Injection_ on headers when using unsanitized input as request headers, more specifically, inside the `content-type` header. Example: ``` import { request } from 'undici' const unsanitizedContentTypeInput = 'application/json\r\n\r\nGET /foo2 HTTP/1.1' await request('http://localhost:3000, { method: 'GET', headers: { 'content-type': unsanitizedContentTypeInput }, }) ``` The above snippet will perform two requests in a single `request` API call: 1) `http://localhost:3000/` 2) `http://localhost:3000/foo2` This issue was patched in Undici v5.8.1. Sanitize input when sending content-type headers using user input as a workaround.

Weakness: CWE-93 (Improper Neutralization of CRLF Sequences), CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2022-35948?

2 open source packages ship an affected version, including undici. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `undici` | npm | All versions | 5.8.2 |
| `undici` | npm | All versions | 5.8.2 |

Products: Nodejs Undici.

## How do I fix CVE-2022-35948?

Upgrade undici to 5.8.2 or later.

## Is CVE-2022-35948 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-35948 exists.

## Other vulnerabilities in Nodejs Undici

- [CVE-2026-109855](https://insights.sbomify.com/CVE-2026-109855/): undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake (high 7.5)
- [CVE-2026-109869](https://insights.sbomify.com/CVE-2026-109869/): undici vulnerable to Denial of Service via unhandled error on excessive content-encodings (high 7.5)
- [CVE-2026-87018](https://insights.sbomify.com/CVE-2026-87018/): undici vulnerable to Denial of Service via TLS 1.2 certificate-changing renegotiation (high 7.5)
- [CVE-2026-19534](https://insights.sbomify.com/CVE-2026-19534/): undici vulnerable to Denial of Service via unrequested WebSocket subprotocol (high 7.5)
- [CVE-2026-12151](https://insights.sbomify.com/CVE-2026-12151/): undici WebSocket client vulnerable to denial of service via fragment count bypass (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2022-35948 and fix it if it is affected.

What it is: CVE-2022-35948 is a medium-severity vulnerability in Nodejs Undici, published on 13 Aug 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-35948 exists.

Affected packages and fixed versions:
- undici (npm): affected all versions; fixed in 5.8.2
- undici (npm): affected all versions; fixed in 5.8.2

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-2022-35948/ (Markdown: https://insights.sbomify.com/CVE-2022-35948/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2022-35948
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2022-35948
- OSV: https://osv.dev/vulnerability/CVE-2022-35948

---
From sbomify Insights: https://insights.sbomify.com/CVE-2022-35948/
Summaries are generated and may contain mistakes; the official description above is the record.