CVE-2025-7339Public exploit

Header manipulation via flat-array misinterpretation

Published Jul 17, 2025 · Updated Jul 17, 2025

Improper array handling in on-headers before 1.1.0 allows local users to alter HTTP response headers through response.writeHead(). The setHeadersFromArray function treats a supported flat key-value array as a two-dimensional array, passing individual characters to setHeader as names and values. Exploitation requires high privileges and an application path that supplies array-form headers while the middleware wraps writeHead; consequences are limited to header integrity and disclosure.

CVSS severity3.4
Low
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper array handling in on-headers before 1.1.0 allows local users to alter HTTP response headers through response.writeHead(). The setHeadersFromArray function treats a supported flat key-value array as a two-dimensional array, passing individual characters to setHeader as names and values. Exploitation requires high privileges and an application path that supplies array-form headers while the middleware wraps writeHead; consequences are limited to header integrity and disclosure.

The record

CVE
CVE-2025-7339
Published
Jul 17, 2025
Updated
Jul 17, 2025
Vendor
jshttp
Product
on-headers
Classifications
CWE-241, T1565.003
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 17, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.1.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

jshttp · on-headersversion=0 <1.1.0

Published CVSS scores

3.4OpenJS FoundationCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-241Improper Handling of Unexpected Data Type
T1565.003Runtime Data Manipulation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo