CVE-2023-45143

What it is

Undici is an HTTP/1.1 client written from scratch for Node.js. Prior to version 5.26.2, Undici already cleared Authorization headers on cross-origin redirects, but did not clear `Cookie` headers. By design, `cookie` headers are forbidden request headers, disallowing them to be set in RequestInit.headers in browser environments. Since undici handles headers more liberally than the spec, there was a disconnect from the assumptions the spec made, and undici's implementation of fetch. As such this may lead to accidental leakage of cookie to a third-party site or a malicious attacker who can control the redirection target (ie. an open redirector) to leak the cookie to the third party site. This was patched in version 5.26.2. There are no known workarounds.

At a glance

Exploitability

Can be exploited over the network with an admin-level account, but needs a user to act. Limited direct impact.

Exploit odds

1.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-10-12 17:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 06:28 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 1.4% in the next 30 days (EPSS).
• Severity: 3.9 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-10-12 17:15 UTC

Last modified

2026-06-17 06:28 UTC

Exploit probability

1.4% · EPSS, next 30 days

Weakness

CWE-200 · Information exposure

Record status

Modified

Affected

• Nodejs Undici < 5.26.2
• Fedoraproject Fedora 37
• Fedoraproject Fedora 38
• Fedoraproject Fedora 39

Attack profile CVSS 3.1 · 3.9

Attack vector

Network

Complexity

High

Privileges needed

High

User interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-45143.md and follow it. Check whether this project is affected by CVE-2023-45143. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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