API Access Vulnerability in Decidim Framework Affects Public Resources
CVE-2026-40870

7.5HIGH

Key Information:

Vendor

Decidim

Status
Decidim
Vendor
CVE Published:
21 April 2026

What is CVE-2026-40870?

The Decidim framework contains an improper access control vulnerability in its API that allows unsecured access to the root-level commentable field. This flaw permits unauthenticated users to access all commentable resources, putting potentially sensitive information at risk, particularly in non-public environments. If the API endpoint is left unsecured, instances running vulnerable versions of Decidim may expose data to unauthorized users. The remediation involves updating to versions 0.30.5 or 0.31.1, which address this vulnerability. Alternatively, securing the API with authentication can limit exposure, although this may require custom code or a third-party module. Organizations are encouraged to implement these fixes promptly to safeguard their platforms.

Affected Version(s)

decidim > 0.31.0.rc1, < 0.31.1 > 0.31.0.rc1, 0.31.1

decidim >= 0.0.1, < 0.30.5 < 0.0.1, 0.30.5

References

https://github.com/decidim/decidim/security/advisories/GH...
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CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.