CVE Tools
Sign in

CVE-2025-30218

Next.js may leak x-middleware-subrequest-id to external hosts

Published: Apr 2, 2025Updated: Sep 10, 2025 Sources: CVE List NVD GHSA BDUCWE-200
NVD MITRE
5.9CVSSMEDIUM
EPSS Score
0.3%
Top 74.0%
CISA KEV
Not in KEV
Exploits
2 Known
Remediation
Patch Available

Description

Next.js is a React framework for building full-stack web applications. To mitigate CVE-2025-29927, Next.js validated the x-middleware-subrequest-id which persisted across multiple incoming requests. However, this subrequest ID is sent to all requests, even if the destination is not the same host as the Next.js application. Initiating a fetch request to a third-party within Middleware will send the x-middleware-subrequest-id to that third party. This vulnerability is fixed in 12.3.6, 13.5.10, 14.2.26, and 15.2.4.

CVSS Vector Breakdown

AV:NAC:HPR:NUI:NS:UC:HI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:NIntegrity
None
A:NAvailability
None
Open in CVSS calculator →

Weaknesses

CWE-200

Affected Products

next.jsvercel
LibraryLibrary
OSS Libraries / web-framework
Next.jsVercel
LibraryLibrary
OSS Libraries / web-framework
nextnpmOSS Libraries
vercelcommercialUSOSS Librariesaka vercel
npmpackage-ecosystemOSS Libraries

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

2 exploit sources identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

1 technique
Collection
View detailed technique mapping

References

https://github.com/vercel/next.js/security/advisories/GHSA-223j-4rm8-mrmf
github.com
https://vercel.com/changelog/cve-2025-30218-5DREmEH765PoeAsrNNQj3O
vercel.com
https://nvd.nist.gov/vuln/detail/CVE-2025-30218
nvd.nist.gov
and 1 more references View all →

Timeline

Published
Apr 2, 2025
Last Updated
Sep 10, 2025

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2025-30218 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows