[Stream] Adding origin restrictions for media transformations (#22409)

* [Stream] Adding origin restrictions for media transformations

* Update src/content/changelog/stream/2025-05-14-media-transformations-origin-restrictions.mdx

Co-authored-by: Denise Peña <[email protected]>

* Update src/content/changelog/stream/2025-05-14-media-transformations-origin-restrictions.mdx

Co-authored-by: Denise Peña <[email protected]>

* Update src/content/changelog/stream/2025-05-14-media-transformations-origin-restrictions.mdx

Co-authored-by: Denise Peña <[email protected]>

---------

Co-authored-by: Denise Peña <[email protected]>

Author: tsmith512

src/content/changelog/stream/2025-05-14-media-transformations-origin-restrictions.mdx

@@ -0,0 +1,27 @@
+---
+title: Introducing Origin Restrictions for Media Transformations
+description: >
+  Control which sources can be used for original media when requesting transformations.
+date: 2025-05-14T12:00:00Z
+---
+
+We are adding [source origin restrictions](/stream/transform-videos/sources/) to
+the Media Transformations beta. This allows customers to restrict what sources
+can be used to fetch images and video for transformations. This feature is the
+same as --- and uses the same settings as ---
+[Image Transformations sources](/images/transform-images/sources/).
+
+When transformations is first enabled, the default setting only allows
+transformations on images and media from the same website or domain being used to make
+the transformation request. In other words, by default, requests to
+`example.com/cdn-cgi/media` can only reference originals on `example.com`.
+
+![Enable allowed origins from the Cloudflare dashboard](~/assets/images/images/allowed-origins.png)
+
+Adding access to other sources, or allowing any source,
+[is easy to do](/images/transform-images/sources/)
+in the **Transformations** tab under **Stream**. Click each domain enabled for
+Transformations and set its sources list to match the needs of your content. The
+user making this change will need permission to edit zone settings.
+
+For more information, learn about [Transforming Videos](/stream/transform-videos/).