CVE-2026-8382

Advanced Custom Fields (ACF®) <= 6.8.1 - Unauthenticated Arbitrary Post Modification via Front-End Form '_post_title' and '_post_content' Parameters

2026-05-30 14:23
Sarawut Poolkhet (MisterHelloz)

Strategic Overview

Status
Patched in 6.8.2
Affected Plugin
Advanced Custom Fields (ACF®)
Affected Version
<= 6.8.1
CVSS
5.3Medium
Weakness type
CWE-862 · Missing Authorization
CVE
CVE-2026-8382
View all Advanced Custom Fields (ACF®) vulnerabilities

At a glance

CVE-2026-8382 is a medium-severity Missing Authorization vulnerability in the Advanced Custom Fields (ACF®) WordPress plugin, affecting versions <= 6.8.1. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 6.8.2; sites on affected versions should update now. Disclosed May 2026, reported by Sarawut Poolkhet (MisterHelloz).

Vulnerability Overview

The Advanced Custom Fields (ACF®) plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 6.8.1. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to overwrite the post_title and post_content of any post bound to a publicly accessible acf_form() instance by injecting values into the _post_title and _post_content parameters of a form submission request.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-862: Missing Authorization

Advanced Custom Fields (ACF®) <= 6.8.1 carries this weakness at acf_form(), and reaching it takes no account at all. A missing authorization check means a function is reachable by anyone who can reach the endpoint, because the code never asks whether the caller is allowed to perform the action.

Any user who can reach the endpoint gets to run an action reserved for higher-privileged roles, from reading protected data to changing settings or content. For Advanced Custom Fields (ACF®) the fix is 6.8.2: builds <= 6.8.1 are affected, anything from 6.8.2 onward is not.

Remediation

Update to version 6.8.2, or a newer patched version

How does WordSec protect against this?

This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: Advanced Custom Fields (ACF®) 6.8.2 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-8382https://www.wordfence.com/threat-intel/vulnerabilities/id/ddb2290d-d4bd-4f70-9fe9-927f49721811https://nvd.nist.gov/vuln/detail/CVE-2026-8382

Related records

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