Advanced Custom Fields - Security Vulnerability (CVE-2026-120534)

Q: Am I affected by this vulnerability?

You are affected if your site runs Advanced Custom Fields. No account is needed to exploit this, so a public site is reachable by anyone.

Q: How do I fix it?

Update Advanced Custom Fields to the latest available version. Where the vendor has not yet published a fix, remove or disable the plugin until they do. Until you can update, Request / payload inspection (WAF) in Hack Halt ProSecure contains this class of attack at the request layer.

Q: What can an attacker actually do?

This is a Remote Code Execution flaw. An attacker who exploits it can run their own code on the server, which is total control of the site.

CVE-2026-120534

Vulnerability CVE-2026-120534 PLUGIN advanced-custom-fields CRITICAL

The Advanced Custom Fields: Extended PRO plugin for WordPress is vulnerable to Limited Code Injection in all versions up to, and including, 0.9.2.6 via the render_field function. This is due to insufficient validation of form configuration parameters before merging into field settings and passing to call_user_func_array in the render_field method. This makes it possible for unauthenticated attackers to call arbitrary WordPress functions with controlled arguments. Method 1 requires the administrator to enable the non-default 'shortcode_preview' setting for the target form, while Method 2 requires the server environment to lack OpenSSL functions, causing ACF Pro's acf_decrypt to fall back to unverified base64 decoding.

CVE-2026-120534

CRITICAL CVSS 9.8 Published 2026-11-03 Updated 2026-11-03

AI Risk Critical (100/100) Active Exploit: No strong signal Published Exploit: No public exploit references Priority: P1 Immediate

Severity Band CRITICAL

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Components 1

Reference Links 2

AI Risk Engine Critical (100/100)

Exploitability Very High

Active Exploitation No strong signal

Published Exploit Status No public exploit references

Threat Timeline

2026-11-03 CVE published and first recorded in the threat feed.
2026-11-03 Record updated with latest vulnerability metadata.
2026-11-12 AI technical context refreshed for mitigation and impact guidance.
Now Monitoring for follow-up changes, linked references, and new related CVEs.

AI Context

Machine-generated threat intelligence

AI Updated 17 hours ago

AI enriched 17 hours ago (2026-11-12 02:28 UTC)

Technical Summary

Potential Impact

Severity is CRITICAL (CVSS 9.8). Depending on deployment context, affected components may be exposed to unauthorized actions or data integrity risk.

Exploitability Assessment

Exploitability is assessed as Very High based on remote code execution potential, low-bar exploit prerequisites.

Primary risk drivers: remote code execution potential, low-bar exploit prerequisites

Mitigation Recommendations

Validate affected product versions, prioritize patching, and monitor references for vendor remediation guidance. If immediate patching is not possible, apply compensating controls and limit exposure of vulnerable surfaces.

Detection & Monitoring

Track authentication anomalies, unexpected file writes, and suspicious plugin API activity around affected components.

Business Impact Lens

AI risk score 100/100 (Critical, Very High) with priority P1 Immediate. Prioritize remediation where affected components process customer data, admin sessions, or Internet-exposed workflows.

Affected Products

Advanced Custom Fields PLUGIN · advanced-custom-fields Affected: <= 0.9.2.6 Fixed version not specified

References

What to do about this

Patch immediately Serious, and reachable without meaningful privilege.

Fix it

Update Advanced Custom Fields to the latest available version.

Where the vendor has not published a fix yet, disable the plugin until they do.

Cannot update today? Request / payload inspection (WAF) in Hack Halt ProSecure blocks this class of attack before WordPress processes the request.

Inspect request parameters and bodies for injection, traversal and file-inclusion payloads, and refuse the request rather than logging it.

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Not sure if you are affected?

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Am I affected by this vulnerability?