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Vulnerability details

5.3/10
CVSS 3.1
GHSA-mx8g-39q3-5c79
false_positive Published 2026-06-17 Updated 2026-06-17
GitHub Advisory
Vulnerability Data from Dependency-Track
Affected versions
Score
5.3 CVSS 3.1 GITHUB CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 `webpack-dev-server` 5.2.5. ### 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.
Same vulnerability as
CVE-2026-9595 false_positive according to EUVD-2026-36729
Analysis Read only
The analysis can only be edited by the BlueMind security teams: log in.

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