CVE-2026-13042 RPB Chessboard <= 8.1.2 - Unauthenticated Stored Cross-Site Scripting via Comment Content
Unauthenticated attackers can inject arbitrary scripts via comment content in the RPB Chessboard plugin, leading to potential account takeover.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-13042?
CVE-2026-13042 is a high-severity cross-site scripting vulnerability in yo35 RPB Chessboard, published on 16 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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 <a> 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.
Weakness: CWE-79
Which versions are affected by CVE-2026-13042?
How do I fix CVE-2026-13042?
No fix has been published for CVE-2026-13042 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-2026-13042 being exploited?
There is no known exploitation of CVE-2026-13042 in the wild and no public exploit code.
Sources
Also known as GHSA-23qv-c3w3-qc96.