CVE-2026-5820 MEDIUM

CVE-2026-5820: Zypento Blocks <= 1.0.6 - Authenticated (Author+) Stored Cross-Site Scripting via Table of Contents Block

Vendor Sproutient
Product Zypento Blocks
Weakness CWE-79 · XSS
Published April 22, 2026
Last update April 22, 2026

CVSS base score

6.4/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

What the vulnerability does

01Description

The Zypento Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the Table of Contents block in all versions up to, and including, 1.0.6. This is due to the front-end TOC rendering script reading heading text via `innerText` and inserting it into the page using `innerHTML` without proper sanitization. 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.

Explanation of Vulnerability in Simple Terms

02Summary

Zypento Blocks versions 1.06 and earlier contain a cross-site scripting (XSS) vulnerability that allows authenticated users to inject malicious scripts affecting other users. The vulnerability has a changed scope, meaning the impact extends beyond the vulnerable component itself. An attacker with low-level privileges can inject code that executes in other users' browsers, potentially compromising their sessions or data.

What an attacker can do

03Attacker Capabilities

Inject malicious scripts that execute in other users' browsers, potentially stealing session data or performing actions on their behalf.

Potential impact on your site

04Site Impact

Authenticated users can inject scripts affecting other site visitors; may lead to account compromise or unauthorized actions.

Conditions required to exploit

05Prerequisites

Attacker must have a low-privilege account on the site; no user interaction required from the victim.

Key dates

06Disclosure timeline

April 22, 2026 CVE published
April 22, 2026 Record updated