CVE-2026-45086: Decidim Forms Admin Question Editor Lacks Vulnerability
MODERATECVE-2026-45086 is a MODERATE (CVSS 5.4) forms admin question editor lacks vulnerability (CWE-284: Improper Access Control) affecting Decidim libraries in the RubyGems ecosystem. The issue involves forms admin question editor lacks authorization. Remediation is available by upgrading affected packages to version 0.31.5, 0.32.0.
CVE-2026-45086 at a Glance
Security Impact
CVSS: 5.4
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N).
How to Fix CVE-2026-45086
To remediate this vulnerability, upgrade all affected Decidim dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade decidim-demographics to 0.31.5Upgrade decidim-demographics to 0.32.0Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for decidim-demographicsHow to Check if You Are Affected
To determine whether your application is affected by CVE-2026-45086, inspect your project dependencies for Decidim:
inspect dependencies for decidim-demographicsAnalyze the terminal output to locate any version of Decidim in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.31.5), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-284: Improper Access Control, where the product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. In Decidim, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-45086 Affected Decidim Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
decidim-demographics
|
RubyGems |
≥ 0.31.0
< 0.31.5
|
0.31.5
|
|
decidim-demographics
|
RubyGems |
≥ 0.32.0.rc1
< 0.32.0
|
0.32.0
|
References
Frequently Asked Questions
What is CVE-2026-45086?
Which Decidim versions are affected?
What version fixes CVE-2026-45086?
Is decidim-demographics affected?
What is the CVSS score of CVE-2026-45086?
What CWE is associated with CVE-2026-45086?
How can I check RubyGems dependencies for CVE-2026-45086?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-vq6j-hj8w-7v39",
"modified" : "2026-07-13T16:51:05Z",
"published" : "2026-07-13T16:51:05Z",
"aliases" : [ "CVE-2026-45086" ],
"summary" : "Decidim: Forms admin question editor lacks authorization",
"details" : "## Description\n\nA participant can load the demographics questionnaire admin editor and make changes.\n\n## Technical description\n\nThe demographics questionnaire editor should require admin access, but the route under `/admin/demographics/questions` renders the editor interface without checking whether the caller is an admin. A normal participant can load the page and see the live update form action, which proves the protected interface is reachable.\n\nReproduction steps:\n\nStep 1. Sign in as a normal participant: Open `http://localhost:3000/users/sign_in`.\nStep 2. Request the admin-only editor directly. Open `http://localhost:3000/admin/demographics/questions/edit_questions` in the same browser.\nStep 3. Add another question:\n\n<img width=\"1522\" height=\"1174\" alt=\"decidim-questions-01\" src=\"https://github.com/user-attachments/assets/923f85d4-0e2f-4511-a9f3-a92f74dbf1d8\" />\n\nNote that access was denied when attempting to see question responses or settings.\n\n### Impact\n\n- Low-privilege users can access questionnaire-admin interfaces.\n- They can read question-management surfaces that should remain limited to questionnaire managers.\n \n### Patches\n\nSee https://github.com/decidim/decidim/pull/16665 \n\n### Workarounds\n\nDisable the \"decidim-demographics\" module \n\n### Reference\n\nOWASP A01:2021 Broken Access Control\n\n### Credits\n\nThis issue was discovered in a security audit organized by the [Decidim Association](https://decidim.org) and made by [Radically Open Security](https://www.radicallyopensecurity.com/) against Decidim financed by [NGI](https://ngi.eu/).",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "RubyGems",
"name" : "decidim-demographics"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0.31.0"
}, {
"fixed" : "0.31.5"
} ]
} ]
}, {
"package" : {
"ecosystem" : "RubyGems",
"name" : "decidim-demographics"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0.32.0.rc1"
}, {
"fixed" : "0.32.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/decidim/decidim/security/advisories/GHSA-vq6j-hj8w-7v39"
}, {
"type" : "WEB",
"url" : "https://github.com/decidim/decidim/pull/16665"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/decidim/decidim"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-284" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-07-13T16:51:05Z",
"nvd_published_at" : null
}
}