TI-2026-19249 Aliases CVE-2026-23891 GHSA-fc46-r95f-hq7g

Decidim has a Cross-site scripting (XSS) vulnerability via user name field

MEDIUM 40CWE-79Published 2026-04-13 · Updated 2026-04-14

Key facts

Attack vector: Network
Privileges required: Low
User interaction: Passive
Attack complexity: Low
Attack requirements: None
Impact type: Cross-site scripting
Confidentiality · integrity · availability: High · High · Low
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00356 29th percentileScored 2026-11-07

Fix Fixed decidim (decidim): 0.31.1, 0.30.5decidim-core (RubyGems): 0.31.1, 0.30.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
decidim	decidim	0.31.0.rc1 to before 0.31.1; before 0.30.5	0.31.1, 0.30.5	Patch available	CNA
—	decidim-core (RubyGems)	0.31.0.rc1 to before 0.31.1	0.31.1	Patch available	GHSA-fc46-r95f-hq7g
—	decidim-core (RubyGems)	before 0.30.5	0.30.5	Patch available	GHSA-fc46-r95f-hq7g

decidim Vendordecidim Affected 0.31.0.rc1 to before 0.31.1; before 0.30.5 Fixed in 0.31.1, 0.30.5 Patch available CNA
decidim-core (RubyGems) Vendor— Affected 0.31.0.rc1 to before 0.31.1 Fixed in 0.31.1 Patch available GHSA-fc46-r95f-hq7g
decidim-core (RubyGems) Vendor— Affected before 0.30.5 Fixed in 0.30.5 Patch available GHSA-fc46-r95f-hq7g

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:decidim:decidim::::::ruby::*	before 0.30.5; 0.31.0 to before 0.31.1	Vulnerable	decidim

cpe:2.3:a:decidim:decidim:*:*:*:*:*:ruby:*:* Versions before 0.30.5; 0.31.0 to before 0.31.1 Vulnerable ·decidim

Remediation

Fix · CNA decidim (decidim) Fixed in 0.31.1, 0.30.5
Fix · GHSA-fc46-r95f-hq7g decidim-core (RubyGems) Fixed in 0.31.1 Advisory →
Fix · GHSA-fc46-r95f-hq7g decidim-core (RubyGems) Fixed in 0.30.5 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-23891
2026-10-03 Alias added: GHSA-fc46-r95f-hq7g

References

Advisory 2

Other 4

TI-2025-40203 Decidim's private data exports can lead to data leaks CVSS 4.0HIGH 8.2
TI-2023-16936 Decidim vulnerable to sensitive data disclosure CVSS 3.1HIGH 7.5
TI-2023-18306 Decidim has broken access control in templates CVSS 3.1CRITICAL 9.1
TI-2023-16935 Decidim Cross-site Scripting vulnerability in the processes filter CVSS 3.1HIGH 8.1
TI-2023-15969 Decidim Cross-site Scripting vulnerability in the external link redirections CVSS 3.1HIGH 8.1
TI-2026-29525 Decidim amendments can be accepted or rejected by anyone CVSS 3.1HIGH 7.5

See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences