GHSA-f5vj-f2hx-8m93

Description

### Impact The internal `/webpack-dev-server/open-editor` and `/webpack-dev-server/invalidate` endpoints perform state-changing actions on any `GET` request, without verifying that the request originated from the dev server's own page. Any website a developer visits while the dev server is running can trigger them cross-origin with no interaction beyond the visit. An attacker can open an arbitrary existing local file in the developer's editor, including files outside the project root (e.g. `~/.ssh/config`). The file's contents are not returned to the attacker. Repeated requests can also spawn editor processes and force recompilations, degrading the developer's machine. ### Patches Fixed in `webpack-dev-server` 5.2.6 by rejecting cross-site requests to the `/webpack-dev-server/open-editor` and `/webpack-dev-server/invalidate` endpoints (see [PR #5698](https://github.com/webpack/webpack-dev-server/pull/5698)). ### Workarounds None