Stored cross-site scripting in YMC Filter plugin for WordPress
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
The YMC Filter plugin for WordPress is affected in all versions up to and including 3.12.19. Insufficient input sanitization and output escaping of the post_title parameter lets injected scripts persist in pages (CWE-79). An authenticated attacker with Author access or higher can store a script that runs when a user opens an injected page. The autocomplete REST endpoint has a permission callback that always returns true, so any site visitor can trigger the stored payload by typing in the YMC filter search box.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| wssoffice21 | YMC Filter | up to 3.12.19 | — | No fix listed | CNA |
- YMC Filter Vendorwssoffice21 Affected up to 3.12.19 Fixed in — No fix listed CNA
Remediation
The sources list no fixed version for YMC Filter.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Timeline
- 2026-10-18 Threatist record created from CVE-2026-109983
- 2026-10-18 Alias added: GHSA-r26w-hjm4-pvpr
References
Other 7
- https://www.wordfence.com/threat-intel/vulnerabilities/id/27cfa62d-ba16-4344-be0c-82cac4d21d1c?source=cve
- https://plugins.trac.wordpress.org/browser/ymc-smart-filter/tags/3.12.19/ymc2/src/api/controllers/frontend/FG_REST_Frontend_Search_Controller.php#L148
- https://plugins.trac.wordpress.org/browser/ymc-smart-filter/tags/3.12.19/ymc2/src/api/abstracts/FG_REST_Abstract_Controller.php#L66
- https://plugins.trac.wordpress.org/browser/ymc-smart-filter/tags/3.12.19/ymc2/assets/js/frontend/ymc-public.min.js#L10
- https://plugins.trac.wordpress.org/browser/ymc-smart-filter/tags/3.12.19/ymc2/src/api/controllers/frontend/FG_REST_Frontend_Search_Controller.php#L135
- https://wordpress.org/plugins/ymc-smart-filter
- https://plugins.trac.wordpress.org/browser/ymc-smart-filter/tags/3.12.20/ymc2/src/api/controllers/frontend/FG_REST_Frontend_Search_Controller.php
More wssoffice21 vulnerabilities
- TI-2024-11622 States Map US <= 2.4.2 - Authenticated (Contributor+) Stored Cross-Site Scripting CVSS 3.1MEDIUM 6.4
- TI-2025-09443 Filter & Grids <= 3.2.0 - Unauthenticated SQL Injection CVSS 3.1MEDIUM 5.9
Sources
- CVE-2026-109983 · CVE Program
- CVE-2026-109983 · NVD
- FIRST EPSS
- GHSA-r26w-hjm4-pvpr · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences