XSS in Decidim
CVE-2026-23891
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.004 (26.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Decidim — versions >= 0.31.0.rc1, < 0.31.1, < 0.30.5
Weakness classification (CWE)
References
- github.com/decidim/decidim/security/advisories/GHSA-fc46-r95f-hq7g (Vendor Advisory)
- github.com/decidim/decidim/releases/tag/v0.30.5 (Product, Release Notes)
- github.com/decidim/decidim/releases/tag/v0.31.1 (Product, Release Notes)
Frequently asked questions
- What is CVE-2026-23891?
- CVE-2026-23891 is a high-severity vulnerability in Decidim, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2026-04-13.
- How severe is CVE-2026-23891?
- High severity. CVSS v3 base score is 8.7 out of 10.