CVE-2026-12428 Missing authorization in Blocks for ACF Fields — Display Custom Fields in the Block Editor
Authenticated attackers with Author-level access can read arbitrary ACF field values from private or other users' posts due to missing authorization checks.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-12428?
CVE-2026-12428 is a medium-severity missing authorization vulnerability in gamaup Blocks for ACF Fields — Display Custom Fields in the Block Editor, published on 9 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
The Blocks for ACF Fields plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the get_all_values() function in the /wp-json/acf-field-blocks/v1/values REST endpoint in versions up to, and including, 1.6.2. The permission_callback only verifies the generic publish_posts capability and the handler passes a user-supplied id parameter directly to get_field_objects() without verifying that the requesting user is authorized to read the target object. This makes it possible for authenticated attackers, with Author-level access and above, to read ACF field values from arbitrary posts (including private posts, drafts, posts by other users, and other ACF-supported objects) that they should not have access to.
Weakness: CWE-862
Which versions are affected by CVE-2026-12428?
How do I fix CVE-2026-12428?
No fix has been published for CVE-2026-12428 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-12428 being exploited?
There is no known exploitation of CVE-2026-12428 in the wild and no public exploit code.
Sources
Also known as GHSA-8mgm-62qj-rh6h.