---
id: "CVE-2026-109983"
kind: "vulnerability"
aliases: ["CVE-2026-109983"]
title: "YMC Filter WordPress plugin: stored XSS via post title field"
severity: "medium"
cvss: 6.4
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["package", "self-hosted", "wordpress", "wordpress-plugins"]
not_affected_if: ["plugin-not-installed", "plugin-updated"]
published_at: "2026-10-17T08:16:28+00:00"
first_seen_at: "2026-10-23T21:57:14+00:00"
updated_at: "2026-10-25T03:59:37+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109983", "first_seen_at": "2026-10-23T21:57:14+00:00"}]
---

# YMC Filter WordPress plugin: stored XSS via post title field

Versions of the YMC Filter plugin up to and including 3.12.19 fail to sanitize the post_title parameter, so a logged-in author can store a script that runs in visitors' browsers. The autocomplete REST endpoint has a permission callback that always returns true, so any visitor can trigger the payload through the filter search box.

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

## How to check

- Check the installed YMC Filter plugin version in the WordPress admin plugin list, or with `wp plugin get ymc-filter --field=version` (plugin slug assumed; unknown if the sources do not confirm it)
- Review posts by Author-level users for script content in titles
- unknown for other checks, the sources do not say

## Fix

- Update YMC Filter to a version later than `3.12.19` (the first fixed version is unknown from the sources)
- Until patched, restrict Author-level accounts or disable the YMC Filter plugin

## Timeline

- 2026-10-23T21:57:14+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-109983

## From the sources

The YMC Filter plugin for WordPress is vulnerable to Stored DOM-Based Cross-Site Scripting via the 'post_title' parameter in all versions up to, and including, 3.12.19 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The autocomplete REST endpoint is registered with a permission callback that unconditionally returns true, meaning any site visitor — including unauthenticated users — can trigger the payload simply by typing in the YMC filter search box, while only Author-level access is required to store it.

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