What the vulnerability does
01Description
The Magazine Companion plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'headerHtmlTag' attribute in the bnm-blocks/featured-posts-1 block in all versions up to, and including, 1.2.3. This is due to insufficient input sanitization and output escaping when using user-supplied values as HTML tag names. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
Explanation of Vulnerability in Simple Terms
02Summary
Post Blocks & Tools versions 1.2.3 and earlier contain a cross-site scripting vulnerability that allows authenticated users to inject malicious scripts affecting other users on the site. The vulnerability has a changed scope, meaning the impact extends beyond the vulnerable component itself. Site administrators should update to a version newer than 1.2.3 to remediate this issue.
What an attacker can do
03Attacker Capabilities
Inject malicious scripts that execute in other users' browsers and affect site functionality.
Potential impact on your site
04Site Impact
Authenticated attackers can deface content, steal session tokens, or redirect users without admin intervention.
Conditions required to exploit
05Prerequisites
Attacker must have a low-privilege user account (e.g., contributor or subscriber role).
Key dates
06Disclosure timeline
November 11, 2025
CVE published
April 8, 2026
Record updated
