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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-9595 Detail

Description

Impact: When a user-configured proxy on webpack-dev-server has a broad context (e.g. /) and ws: true, it also intercepts the dev server's own HMR WebSocket and forwards it to the proxy target. This leaks the browser's cookies and Origin header to the backend, bypasses the dev server's Host/Origin validation, and corrupts the HMR socket (both HMR and the proxy end up writing to the same socket). Patches: Fixed in [email protected]. Workarounds: Scope user-defined proxy context to specific paths instead of /, or omit ws: true from the proxy entry when WebSocket forwarding is not required.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://cna.openjsf.org/security-advisories.html openjs Vendor Advisory 
https://github.com/facebook/create-react-app/pull/7444 openjs Issue Tracking  Patch 
https://github.com/vuejs/vue-cli/commit/72ba7505aff2a8314e82aa5082379a77504a1fcb openjs Patch 
https://github.com/webpack/webpack-dev-server/pull/4316 openjs Issue Tracking  Patch 
https://github.com/webpack/webpack-dev-server/security/advisories/GHSA-mx8g-39q3-5c79 openjs Mitigation  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-346 Origin Validation Error openjs  
CWE-441 Unintended Proxy or Intermediary ('Confused Deputy') openjs  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-9595
NVD Published Date:
06/15/2026
NVD Last Modified:
06/16/2026
Source:
openjs