github.com
https://github.com/decidim/decidim CVE-2026-23891
CRITICAL
Decidim has a Cross-site scripting (XSS) vulnerability via user name field
Record summary
CVE-2026-23891 has a selected CVSS score of 9.3 (critical).
Description
Decidim is a participatory democracy framework. In versions below 0.30.5 and 0.31.0.rc1 through 0.31.0, a stored code execution vulnerability in the user name field allows a low-privileged attacker to execute arbitrary code in the context of any user who passively visits a comment page, resulting in high confidentiality and integrity impact across security boundaries. This issue has been fixed in versions 0.30.5 and 0.31.1.
Description source: CVE List
Exploitation context
CISA SSVC decision
ExploitationNone
AutomatableNo
Technical impactPartial
CISA Coordinator · SSVC 2.0.3 · Evaluated Apr 14, 2026 · Source: CVE List
Affected products and versions
2| Product | Source | Version range | Status |
|---|---|---|---|
decidimBrowse decidim / decidim | CVE List | >= 0.31.0.rc1, < 0.31.1 | affected |
| < 0.30.5 | affected | ||
decidim-coreBrowse RubyGems / decidim-core | GitHub Advisory | 0.31.0.rc1 to < 0.31.1 · Fixed in 0.31.1 | affected |
| Before 0.30.5 · Fixed in 0.30.5 | affected |
References
6github.com
https://github.com/decidim/decidim/releases/tag/v0.30.5 github.com
https://github.com/decidim/decidim/releases/tag/v0.31.1 github.comConfirmation
https://github.com/decidim/decidim/security/advisories/GHSA-fc46-r95f-hq7g github.com
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/decidim-core/CVE-2026-23891.yml nvd.nist.gov
https://nvd.nist.gov/vuln/detail/CVE-2026-23891