CVE-2023-24807 Undici vulnerable to Regular Expression Denial of Service in Headers
Attackers can cause denial of service in Node.js applications using Undici by sending crafted headers that trigger inefficient regex processing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-24807?
CVE-2023-24807 is a high-severity denial of service vulnerability in Nodejs Undici, published on 16 Feb 2023. 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 for Node.js. Prior to version 5.19.1, the `Headers.set()` and `Headers.append()` methods are vulnerable to Regular Expression Denial of Service (ReDoS) attacks when untrusted values are passed into the functions. This is due to the inefficient regular expression used to normalize the values in the `headerValueNormalize()` utility function. This vulnerability was patched in v5.19.1. No known workarounds are available.
Which versions are affected by CVE-2023-24807?
2 open source packages ship an affected version, including undici. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
undici npm | All versions | 5.19.1 |
undici npm | All versions | 5.19.1 |
Products include Nodejs Undici.
How do I fix CVE-2023-24807?
Upgrade undici to 5.19.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-24807 being exploited?
There is no known exploitation of CVE-2023-24807 in the wild and no public exploit code.
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 ALPINE-CVE-2023-24807, AZL-13585, CLEANSTART-2026-DR81421, CLEANSTART-2026-NQ17832, DEBIAN-CVE-2023-24807, GHSA-r6ch-mqf9-qc9w.