← Vulnerability feed

Vulnerability record · CVE-2026-40869 · published 21 April 2026

CVE-2026-40869: Decidim vulnerability

Decidim · Decidim

Decidim is a participatory democracy framework. Starting in version 0.19.0 and prior to versions 0.30.5 and 0.31.1, a vulnerability allows any registered and authenticated user to accept or reject any amendments. The impact is on any users who have created proposals where the amendments feature is enabled. This also elevates the user accepting the amendment as the author of the original proposal as people amending proposals are provided coauthorship on the coauthorable resources. Versions 0.30.5 and 0.31.1 fix the issue. As a workaround, disable amendment reactions for the amendable component (e.g. proposals).

6.5 CVSS 3.1 Medium EPSS 0.31% · top 78.1% CWE-266 · CWE-266
6.5CVSS 3.1 base score
0.31%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
2References
17 Jun 2026Last modified by NVD

Description

Decidim is a participatory democracy framework. Starting in version 0.19.0 and prior to versions 0.30.5 and 0.31.1, a vulnerability allows any registered and authenticated user to accept or reject any amendments. The impact is on any users who have created proposals where the amendments feature is enabled. This also elevates the user accepting the amendment as the author of the original proposal as people amending proposals are provided coauthorship on the coauthorable resources. Versions 0.30.5 and 0.31.1 fix the issue. As a workaround, disable amendment reactions for the amendable component (e.g. proposals).

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/decidim/decidim/commit/1b99136a1c7aa02616a0b54a6ab88d12907a57a9 Patch
https://github.com/decidim/decidim/security/advisories/GHSA-w5xj-99cg-rccm MitigationPatchVendor Advisory

Track CVE-2026-40869 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.3CVE-2026-23891Decidim cross-site scripting vulnerabilityDecidim 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 …EPSS 0.36%8.2CVE-2025-65017Decidim information exposure vulnerabilityDecidim is a participatory democracy framework. In versions from 0.30.0 to before 0.30.4 and from 0.31.0.rc1 to before 0.31.0, the private data expor…EPSS 0.28%7.5CVE-2023-34090Decidim information exposure vulnerabilityDecidim is a participatory democracy framework, written in Ruby on Rails, originally developed for the Barcelona City government online and offline p…EPSS 1.3%7.4CVE-2023-48220Decidim vulnerabilityDecidim is a participatory democracy framework. Starting in version 0.4.rc3 and prior to version 2.0.9 of the `devise_invitable` gem, the invites fea…EPSS 0.79%7.1CVE-2023-36465Decidim improper access control vulnerabilityDecidim is a participatory democracy framework, written in Ruby on Rails, originally developed for the Barcelona City government online and offline p…EPSS 0.54%6.1CVE-2023-34089Decidim cross-site scripting vulnerabilityDecidim is a participatory democracy framework, written in Ruby on Rails, originally developed for the Barcelona City government online and offline p…EPSS 0.74%6.1CVE-2023-32693Decidim cross-site scripting vulnerabilityDecidim is a participatory democracy framework, written in Ruby on Rails, originally developed for the Barcelona City government online and offline p…EPSS 0.82%5.7CVE-2023-47635Decidim server-side request forgery (ssrf) vulnerabilityDecidim is a participatory democracy framework. Starting in version 0.23.0 and prior to versions 0.27.5 and 0.28.0, the CSRF authenticity token check…EPSS 0.31%

Source: NIST National Vulnerability Database (record CVE-2026-40869), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.