CVE-2025-7339

What it is

on-headers is a node.js middleware for listening to when a response writes headers. A bug in on-headers versions `<1.1.0` may result in response headers being inadvertently modified when an array is passed to `response.writeHead()`. Users should upgrade to version 1.1.0 to receive a patch. Uses are strongly encouraged to upgrade to `1.1.0`, but this issue can be worked around by passing an object to `response.writeHead()` rather than an array.

At a glance

Exploitability

Can be exploited locally on the machine with an admin-level account. Limited direct impact.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

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

Timeline

1. 2025-07-17 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 10:04 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 3.4 LOW (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-07-17 16:15 UTC

Last modified

2026-06-17 10:04 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-241

Record status

Deferred

Attack profile CVSS 3.1 · 3.4

Attack vector

Local

Complexity

Low

Privileges needed

High

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

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-2025-7339.md and follow it. Check whether this project is affected by CVE-2025-7339. 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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