CVE-2026-109983 YMC Filter <= 3.12.19 - Authenticated (Author+) Stored DOM-Based Cross-Site Scripting via 'post_title' Parameter
Authenticated attackers can inject scripts via post titles that execute for all users, including unauthenticated visitors, due to insufficient sanitization.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-109983?
CVE-2026-109983 is a medium-severity cross-site scripting vulnerability in wssoffice21 YMC Filter, published on 17 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-109983?
How do I fix CVE-2026-109983?
No fix has been published for CVE-2026-109983 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-109983 being exploited?
There is no known exploitation of CVE-2026-109983 in the wild and no public exploit code.
Sources
Also known as GHSA-r26w-hjm4-pvpr.