In eZ Platform v2.3.x it is possible to bypass permission checks in a particular case. This means user data such as name and email (but not passwords or password hashes) can be read by unauthenticated users. This affects only v2.3.x. If you use v2.2.x or older you are not affected.
To install, use Composer to update "ezsystems/repository-forms" to the "Resolving versions" mentioned above, or apply this patch manually:
https://github.com/ezsystems/repository-forms/commit/ea82e136ec1ea40aca714abb79cc8e5bfece01e8
Have you found a security bug in eZ Publish or eZ Platform? See how to report it responsibly here: https://doc.ez.no/Security
eZ Platform users with the Company admin role can assign any role to any user
Critical severity. Users with the Company admin role (introduced by the company account feature in v4) can assign any role to any user. This also applies to any other user that has the role / assign policy. Any subtree limitation in place does not have any effect.
The role / assign policy is typically only given to administrators, which limits the scope in most cases, but please verify who has this policy in your installaton. The fix ensures that subtree limitations are working as intended.