# Release notes for Plone 6.2.0rc1

* Released: March 27th, 2026
* Check the [release schedule](https://plone.org/download/release-schedule).
* Read the [upgrade guide](https://6.docs.plone.org/backend/upgrading/version-specific-migration/upgrade-to-62.html), explaining the biggest changes compared to 6.1.
* Canonical place for these [release notes](https://dist.plone.org/release/6.2.0rc1/RELEASE-NOTES.md) and the full [packages changelog](https://dist.plone.org/release/6.2.0rc1/changelog.txt).

If you want to jump straight in, here are some important links:

* With pip you can use the constraints file at [https://dist.plone.org/release/6.2.0rc1/constraints.txt](https://dist.plone.org/release/6.2.0rc1/constraints.txt).  This includes the extra and ecosystem constraints, which are separate in the Buildout configs.
* With Buildout you can use the versions file at [https://dist.plone.org/release/6.2.0rc1/versions.cfg](https://dist.plone.org/release/6.2.0rc1/versions.cfg), plus optionally [`versions-extra.cfg`](https://dist.plone.org/release/6.2.0rc1/versions-extra.cfg) and [`versions-ecosystem.cfg`](https://dist.plone.org/release/6.2.0rc1/versions-ecosystem.cfg).
* Use Docker image `plone-backend`.


## Please test

This is the first release candidate of Plone 6.2.  We don't recommend this for production use, but please try it out in your projects.  You can report issues in the [`Products.CMFPlone` tracker](https://github.com/plone/Products.CMFPlone/issues/).

Please also test your add-ons on Plone 6.2.  If your package uses namespaces, we recommend that you switch to native namespaces.  This includes all packages in the `collective` namespace.  See the section "Move to native namespaces" in the [upgrade guide](https://6.docs.plone.org/backend/upgrading/version-specific-migration/upgrade-to-62.html).  This should be considered a breaking change, so you should do this in a new major version of your add-on.  Still, as explained in the upgrade guide and below, it should work fine to use such a new major version in Plone 6.0 and 6.1.  But you may need to use `zc.buildout` 5 and/or install `horse-with-no-namespace` in your virtualenv.


## Highlights

These are the main changes compared to 6.2.0a1:

* `lxml`: updated from 5.4.0 to 6.0.2.
  This parses html slightly differently. The update caused [problems in diazo](https://github.com/plone/diazo/pull/92), which have been fixed.
  On Classic UI you should check if your theme still renders correctly.  Most sites are expected to be fine though.
* `plone.app.content`: Alphabetically sort the list of portal types in the constraints configuration form.
* `plone.app.users`: Extract ``generate_user_id`` and ``generate_login_name`` as standalone functions in ``plone.app.users.utils``, enabling reuse from ``plone.api`` and ``plone.restapi`` without form view dependency.
* `plone.app.z3cform`:
  * Remove EmailWidget template and use generic attributes instead.
  * Implement URI widget for `type="url"` inputs.
* `plone.base`:
  * Add boolean utils: `is_truthy` (improved), `is_falsy` and `boolean_value`.
  * Add ``plone.base.interfaces.IAddonList``.
* `plone.exportimport`: Add `@export` and `@import` REST API services.
* `plone.formwidget.recurrence`: Disable additional dates (RDATE) feature in recurrence widget to prevent interoperability issues with Outlook and Android calendar clients when exporting/importing iCal events.
* `plone.namedfile`:
  * Extract `_scale_url()` method on `ImageScale` and `ImageScaling` for overridable scale URL generation.
    Accepts an optional `scale_info` dict with scale metadata (width, height, mode, fieldname, mimetype, etc.).
    With this, custom image backends (e.g. Thumbor) can generate URLs with full context by overriding a single method.
  * Add original image size url in the srcset generated in the srcset method
* `plone.registry`: Add per-request cache for registry value and forInterface proxy lookups, avoiding repeated OOBTree traversals within a single request.
* `plone.restapi`:
  * Services which take boolean parameters now check the input more strictly, using the `boolean_value` util.
  * The `@controlpanel` service now includes `searchable_text` for each control panel.
  * Added support for sorting vocabularies by title before batching for the `@vocabularies` endpoint.
  * Add CSV import and export support to the @users endpoint.
  * Redirect documentation from Read the Docs to https://6.docs.plone.org/plone.restapi/docs/source/.
* `plone.volto`:
  * Add `/@blocktypes` endpoint to expose `block_types` index.
  * Added a `block_types` metadata column to the catalog to include a count for each type.
* `Products.CMFPlone`:
  * `MigrationTool`: Prepare support for custom base profiles without subclassing.
    Make `AddonList` a named utility and register ours under the name `Products.CMFPlone`.
    The utility must have an `addon_list` property and optionally may have a `pre_addon_list`, which gets upgraded before the base profile upgrade.
    Add `MigrationTool.get_profile` method, returning the base profile id that was set, by default `Products.CMFPlone:plone`.
    Add `MigrationTool.get_package_name` method, taking the package name from the profile, so by default `Products.CMFPlone`.
    In `MigrationTool.coreVersions` return `core_package` and `core_version`.  If `core_package` is not `Products.CMFPlone`, show this version in the overview control panel.
  * Resource registry: Allow to use `*` dependencies.
    Earlier we added the `all` keyword for the `depends` attribute of resource registry entries to define a resource which should be loaded after all others.
    In Plone 5 we had the `*` keyword for exactly that.
    This brings now back `*` in addition to `all` for the same purpose.
    This might also allow for a smoother upgrade experience.

These are the main changes compared to 6.1:

* We have switched to native namespaces (also known as implicit namespaces) for `plone.*`, `Products.*`, `collective.*` and all other namespaces.
* We use Zope 6.0b2, pinning versions with native namespaces.
* We have updated `zc.buildout` to version 5, and in the `requirements.txt` we have added `horse-with-no-namespace`.
  That helps avoid problems when not all packages in a namespace are using the same namespace style.
  See also below, in the section about "pip, buildout, setuptools".
* Some templates are being moved to `plone.app.layout`, this is ongoing.  Progress so far:
  * Moved lock info viewlet from `plone.locking`.
  * Modify `plone.protect.confirm` to use a simpler template that does not assume Classic UI is installed.
    The previous template was moved to `plone.app.layout`.
* `icalendar` has various breaking changes, but that should only affect you if you directly interact with that package.
* `plone.restapi`: `@aliases` service: Add support for filtering aliases for a non-root item.
* `plone.volto`: Add larger scales to `plone.allowed_sizes` for new sites. This helps avoid the need to serve the original image which can be very large.
  * `2k` is large enough for a default-width image on a high-density display.
  * `4k` is large enough for a full-width images on high-density viewports up to 2000 pixels wide.
* `Products.isurlinportal`: Prevent URLs that start with more than two slashes to be considered as URLs in portal.
  See [security advisory](https://github.com/plone/Products.isurlinportal/security/advisories/GHSA-43gx-6gv6-3jcp).
* `Products.PluggableAuthService`: Add property to clear session data at login boundary to the session auth helper.  This property defaults to ``False`` to preserve the current behavior.  Clearing session data during login helps mitigate session fixation attacks: https://owasp.org/www-community/attacks/Session_fixation


## Volto frontend

The default frontend for new Plone 6 sites is Volto.
Note that this is a JavaScript frontend that you need to run in a separate process with NodeJS.

Plone 6.2 is meant to be used with Volto 19.
Latest release is [19.0.0-alpha.27](https://www.npmjs.com/package/@plone/volto/v/19.0.0-alpha.27).  See the [changelog](https://github.com/plone/volto/blob/19.0.0-alpha.27/packages/volto/CHANGELOG.md).  This is an alpha release, but it is ready to be made final.  Volto is just waiting for the Plone 6.2 final release.

Please have a look at the [upgrade guide](https://6.docs.plone.org/volto/upgrade-guide/index.html#upgrading-to-volto-19-x-x) for migration from Volto 18 to 19.


## Classic UI

The HTML based and server side rendered UI that was present in Plone 5.2 and earlier major Plone releases is still available and has also been updated and improved upon in Plone 6.  Our documentation now refers to this frontend as 'Classic UI'.

Classic UI related changes:

* `plone.base`:
  * `IClassicUISchema`: Add new control panel.
  * Add "license key" field to TinyMCE schema.
* `plone.app.layout`:
  * Add default GenericSetup profile with `IPloneAppLayout` BrowserLayer.
  * Add the new property `is_ajax` to the Plone layout view.
    This returns True, if an AJAX request is detected. This is done by checking if the `HTTP_X_REQUESTED_WITH` request header is set to `XMLHttpRequest`.
    `plone.app.theming` has related changes.
    Note: this is an unreliable way to detect AJAX requests. While many client-side
    libraries (like jQuery) add this request header automatically, the Fetch API
    does not. When using fetch, it is recommended to wrap it with a helper function
    that adds this header to each request.
* `plone.staticresources`: Update `mockup` from 5.4 to 5.6.0 with TinyMCE 8.  See also [`mockup` 5.6.0 changelog](https://github.com/plone/mockup/releases/tag/5.6.0).
* `plone.classicui`: Install the `plone.app.layout` default profile when creating a site using the classic distribution.


## Python compatibility

This release supports Python 3.10, 3.11, 3.12, 3.13, and 3.14.


## pip, buildout, setuptools

In Plone core we use these versions to install Plone:

```
horse-with-no-namespace==20260202.0
pip==26.0.1
setuptools==81.0.0
wheel==0.46.3
zc.buildout==5.1.3
```

In general you are free to use whatever versions work for you, but these worked for us.

`setuptools` 82.0.0 was released, which removed the `pkg_resources` module.
So if you want to use this `setuptools` version, *none* of the packages that you use should use `pkg_resources` style namespaces.
If that is no problem, then `setuptools` 82 is fine if you use `pip`, but not if you use `zc.buildout`.
The reason is that `zc.buildout` still uses `pkg_resources` code (not its namespaces, but other parts).

On `setuptools` 81 and older, problems start when you have multiple packages in the same namespace, that use different namespace implementations.
Then on startup of Plone you may get an error saying "Package not found".
This depends on what you use to install the packages.
In the following examples, we have two packages in the same namespace, say `ns.native` (using native namespaces) and `ns.deprecated` (using pkg_resources style).

* Make editable installs of both packages (`pip install -e` or in buildout, `develop =`):

  - This works neither in pip nor in buildout.
  - You can install the [`horse-with-no-namespace`](https://pypi.org/project/horse-with-no-namespace/) package to get this working.

* Make a normal install of both packages:

  - This works fine in pip.
  - This fails in buildout 4.x.
  - This works fine in buildout 5.x.

* Make a normal install of one package and an editable install of the other:

  - This works fine in pip.
  - This fails in buildout 4.x.
  - This fails in buildout 5.x as well.  But again, you can use `horse-with-no-namespace` to get this working.

For more explanation, see the [`zc.buildout` 5 readme](https://pypi.org/project/zc.buildout/5.1.1/), the part about
"native namespaces and breaking changes in 5.x".  This is also good to read if you use pip instead of Buildout.


## Installation

For installation instructions, see the [documentation](https://6.docs.plone.org/install/index.html).


## Issues

If you find any issues, please report them in the [main issue tracker](https://github.com/plone/Products.CMFPlone/issues).