CVE-2026-40869
Decidim amendments can be accepted or rejected by anyone
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).
INFO
Published Date :
April 21, 2026, 8:17 p.m.
Last Modified :
April 21, 2026, 8:17 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-40869
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update Decidim to version 0.30.5 or 0.31.1.
- Disable amendment reactions for proposals.
- Review coauthorship assignments on existing proposals.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40869.
| URL | Resource |
|---|---|
| https://github.com/decidim/decidim/commit/1b99136a1c7aa02616a0b54a6ab88d12907a57a9 | |
| https://github.com/decidim/decidim/security/advisories/GHSA-w5xj-99cg-rccm |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40869 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40869
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40869 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40869 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Apr. 21, 2026
Action Type Old Value New Value Added 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). Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Added CWE CWE-266 Added Reference https://github.com/decidim/decidim/commit/1b99136a1c7aa02616a0b54a6ab88d12907a57a9 Added Reference https://github.com/decidim/decidim/security/advisories/GHSA-w5xj-99cg-rccm