Vulnerability · Published Apr 21, 2026 · Assigned by GitHub_M
CVE-2026-40869Decidim amendments can be accepted or rejected by anyone
High 7.5
In plain English
A high-severity security flaw in decidim from decidim. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 13% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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).
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| RubyGems | decidim-core | 0.31.1 | GHSA-w5xj-99cg-rccm |
| RubyGems | decidim-core | 0.30.5 | GHSA-w5xj-99cg-rccm |
Affected products (as reported)
Weakness: CWE-266 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N