---
id: "CVE-2026-127048"
page: "https://infrastack.ai/live/CVE-2026-127048"
kind: "vulnerability"
aliases: ["CVE-2026-127048"]
title: "Custom Block Builder WordPress plugin: unauthenticated REST requests run PHP code"
severity: "critical"
cvss: null
epss: null
exploited: false
status: "open"
category: "other"
products: [{"name": "Custom Block Builder", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["custom-block-builder", "other", "self-hosted", "wordpress"]
not_affected_if: ["plugin-not-installed", "version-3.0.0-or-later"]
published_at: "2026-11-15T07:16:54+00:00"
first_seen_at: "2026-11-15T07:36:12+00:00"
updated_at: "2026-11-15T07:36:17+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-127048", "first_seen_at": "2026-11-15T07:36:12+00:00"}]
exploit_sources: []
---

# Custom Block Builder WordPress plugin: unauthenticated REST requests run PHP code

Link for people: https://infrastack.ai/live/CVE-2026-127048 (this .md is for agents)

The Custom Block Builder WordPress plugin before 3.0.0 has REST routes whose permission checks return a non-error value that WordPress treats as granted. An unauthenticated visitor can therefore execute arbitrary PHP code on the server.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Custom Block Builder affected range not listed fixed no fixed version listed

## How to check

- Check the installed version of the Custom Block Builder plugin in the WordPress admin under Plugins, or in `wp-content/plugins/` for the plugin folder's version header.

## Fix

- Custom Block Builder plugin: move to `3.0.0` or later (the sources state the fix as 'before 3.0.0').

## Timeline

- 2026-11-15T07:36:12+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-127048

## From the sources

The Custom Block Builder  WordPress plugin before 3.0.0 does not properly deny unauthorised requests to its REST routes, as its permission checks return a non-error response that WordPress treats as granted, allowing unauthenticated users to execute arbitrary PHP code on the server.

---

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