Vulnary
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Critical· 9.8

CVE-2026-8809

The Advanced Custom Fields: Extended plugin for WordPress has a critical flaw that lets anyone on the internet create a new administrator account without logging in. The bug is caused by the plugin trusting a POST parameter that can bypass validation checks. If a site exposes a public form that can create users, an attacker can exploit this to gain full control.

publishedMay 28, 2026
last modifiedJul 21, 2026
sourcesNVD
severity · cvss
9.8
critical · how bad it is
exploitation · epss
<1%
53th percentile · chance of exploitation in 30 days
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →
auto-deletes from the system
counting…on Sep 4, 2026

No official fix yet. If none appears within 45 days of first tracking, this entry is removed automatically.

01

Who is affected

WordPress sites using the Advanced Custom Fields: Extended plugin, versions up to and including 0.9.2.5, that have a publicly accessible ACFE frontend form configured with a Create User action.

02

Real-world impact

An attacker can add a new administrator user to the WordPress site, giving them complete control over the site’s content, settings, and any other administrative functions.

03

Why this severity

The CVSS score of 9.8 reflects that the vulnerability can be exploited over the network with no authentication or user interaction, and it allows an attacker to fully compromise confidentiality, integrity, and availability of the WordPress installation.

04

What to do about it

no official fix yet

No official fix or mitigation is documented in the sources yet. Monitor the vendor advisory and apply the patch as soon as it is released.

No fix documented in sources

05

Timeline

  1. May 28, 2026 · May 28, 2026
    Published
    Disclosed and added to the National Vulnerability Database.
  2. Jul 21, 2026 · 14d ago
    Advisory updated
    The NVD record was last revised.
06

How it’s attacked

Attack vectorNetwork (remote)
Attack complexityLow
Privileges requiredNone
User interactionNone needed
ScopeUnchanged
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
07

References & advisories

NVD advisory ↗Search advisories ↗
(ai-assisted) A model wrote this summary from the official data, so double-check it against the source before you act on it. Read the official advisory →