CVE-2022-35949 `undici.request` vulnerable to SSRF using absolute URL on `pathname`
Attackers can exploit SSRF in undici library by manipulating pathname input to redirect requests to internal services, affecting Node.js applications using this HTTP client.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-35949?
CVE-2022-35949 is a medium-severity server-side request forgery vulnerability in Nodejs Undici, published on 12 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` is vulnerable to SSRF (Server-side Request Forgery) when an application takes in **user input** into the `path/pathname` option of `undici.request`. If a user specifies a URL such as `http://127.0.0.1` or `//127.0.0.1` ```js const undici = require("undici") undici.request({origin: "http://example.com", pathname: "//127.0.0.1"}) ``` Instead of processing the request as `http://example.org//127.0.0.1` (or `http://example.org/http://127.0.0.1` when `http://127.0.0.1 is used`), it actually processes the request as `http://127.0.0.1/` and sends it to `http://127.0.0.1`. If a developer passes in user input into `path` parameter of `undici.request`, it can result in an _SSRF_ as they will assume that the hostname cannot change, when in actual fact it can change because the specified path parameter is combined with the base URL. This issue was fixed in `[email protected]`. The best workaround is to validate user input before passing it to the `undici.request` call.
Weakness: CWE-918
Which versions are affected by CVE-2022-35949?
2 open source packages ship an affected version, including undici. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
undici npm | All versions | 5.8.2 |
undici npm | All versions | 5.8.2 |
Products include Nodejs Undici.
How do I fix CVE-2022-35949?
Upgrade undici to 5.8.2 or later.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2022-35949 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2022-35949 exists.
Other vulnerabilities in Nodejs Undici
- CVE-2026-109855 undici WebSocket client vulnerable to Denial of Service via failed HTTP/2 handshake
- CVE-2026-109869 undici vulnerable to Denial of Service via unhandled error on excessive content-encodings
- CVE-2026-87018 undici vulnerable to Denial of Service via TLS 1.2 certificate-changing renegotiation
- CVE-2026-19534 undici vulnerable to Denial of Service via unrequested WebSocket subprotocol
- CVE-2026-12151 undici WebSocket client vulnerable to denial of service via fragment count bypass
Sources
Also known as DEBIAN-CVE-2022-35949, GHSA-8qr4-xgw6-wmr3.