CVE-2026-23891: Decidim stored XSS in user name field

Quick answers

Is CVE-2026-23891 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-23891 being exploited in the wild.

How severe is CVE-2026-23891?

High severity, with a CVSS score of 8.7, published 13 April 2026.

Which products and versions are affected?

decidim-core (RubyGems) ECOSYSTEM:introduced=0.31.0.rc1,fixed=0.31.1.

Is there a fix for CVE-2026-23891?

Yes. decidim-core (RubyGems): upgrade to 0.31.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Am I affected by CVE-2026-23891?

Check whether you run decidim-core (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

• decidim-core (RubyGems): upgrade to 0.31.1 or later

  bundle update decidim-core

Affected products

• decidim-core (RubyGems) ECOSYSTEM:introduced=0.31.0.rc1,fixed=0.31.1

Identifiers

• CVE-2026-23891
• GHSA-fc46-r95f-hq7g

References

• https://api.github.com/users/cyberschnaps
• https://github.com/cyberschnaps
• https://api.github.com/users/cyberschnaps/gists%7B/gist_id%7D
• https://api.github.com/users/cyberschnaps/repos
• https://avatars.githubusercontent.com/u/7559821?v=4
• https://api.github.com/users/cyberschnaps/events%7B/privacy%7D