CVE-2026-40869 json
Decidim amendments can be accepted or rejected by anyone
published 6mo ago modified 4mo ago also EUVD-2026-24251 , GHSA-w5xj-99cg-rccm
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
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).
Patch / fix
- rubygems decidim-core 0.30.5, 0.31.1
- decidim decidim 0.30.5, 0.31.1
Is CVE-2026-40869 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| rubygems | decidim-core | >=0.31.0.rc1, <0.31.1 >=0.19.0, <0.30.5 |
0.31.1 0.30.5 |
Affected products
- decidim decidim
Classification
- Weakness
-
- CWE-266 Incorrect Privilege Assignment
References
-
github.com
/decidim/decidim/commit/1b99136a1c7aa02616a0b54a6ab88d12907a57a9
web, patch
-
github.com
/decidim/decidim/security/advisories/GHSA-w5xj-99cg-rccm
web, mitigation, patch, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-40869
advisory
-
github.com
/decidim/decidim
package
-
github.com
/rubysec/ruby-advisory-db/blob/master/gems/decidim-core/CVE-2026-40869.yml
web
Sources
- CVE List CVE-2026-40869
- GitHub Advisory GHSA-w5xj-99cg-rccm
- NVD CVE-2026-40869
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.