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)
EPSS: 0.004 (28.3th percentile) — read the EPSS interpretation.
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.
Affected products
- Decidim — versions >= 0.31.0.rc1, < 0.31.1, < 0.30.5
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Product, x_refsource_MISC, 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.