high7.5
CVE-2026-40869
Decidim amendments can be accepted or rejected by anyone
Impact
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
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | decidim-core | >= 0.31.0.rc1, < 0.31.1 | 0.31.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Decidim | Decidim | from 0.19.0 before 0.30.5 from 0.31.0 before 0.31.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-w5xj-99cg-rccm
- https://github.com/decidim/decidim/security/advisories/GHSA-w5xj-99cg-rccm
- https://github.com/decidim/decidim/commit/1b99136a1c7aa02616a0b54a6ab88d12907a57a9
- https://nvd.nist.gov/vuln/detail/CVE-2026-40869
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/decidim-core/CVE-2026-40869.yml