📝 Update release notes

Author: tiangolo

docs/en/docs/release-notes.md

@@ -2,7 +2,25 @@
 
 ## Latest Changes
 
-* 🐛 Check Content-Type request header before assuming JSON. PR [#2118](https://github.com/tiangolo/fastapi/pull/2118) by [@patrickkwang](https://github.com/patrickkwang).
+
+### Security fixes
+
+* 🔒 Check Content-Type request header before assuming JSON. Initial PR [#2118](https://github.com/tiangolo/fastapi/pull/2118) by [@patrickkwang](https://github.com/patrickkwang).
+
+This change fixes a [CSRF](https://en.wikipedia.org/wiki/Cross-site_request_forgery) security vulnerability when using cookies for authentication in path operations with JSON payloads sent by browsers.
+
+In versions lower than `0.65.2`, FastAPI would try to read the request payload as JSON even if the `content-type` header sent was not set to `application/json` or a compatible JSON media type (e.g. `application/geo+json`).
+
+So, a request with a content type of `text/plain` containing JSON data would be accepted and the JSON data would be extracted.
+
+But requests with content type `text/plain` are exempt from [CORS](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS) preflights, for being considered [Simple requests](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#simple_requests). So, the browser would execute them right away including cookies, and the text content could be a JSON string that would be parsed and accepted by the FastAPI application.
+
+See [CVE-2021-32677](https://github.com/tiangolo/fastapi/security/advisories/GHSA-8h2j-cgx8-6xv7) for more details.
+
+Thanks to [Dima Boger](https://twitter.com/b0g3r) for the security report! 🙇🔒
+
+### Internal
+
 * 🔧 Update sponsors badge, course bundle. PR [#3340](https://github.com/tiangolo/fastapi/pull/3340) by [@tiangolo](https://github.com/tiangolo).
 * 🔧 Add new gold sponsor Jina 🎉. PR [#3291](https://github.com/tiangolo/fastapi/pull/3291) by [@tiangolo](https://github.com/tiangolo).
 * 🔧 Add new banner sponsor badge for FastAPI courses bundle. PR [#3288](https://github.com/tiangolo/fastapi/pull/3288) by [@tiangolo](https://github.com/tiangolo).