CVE-2026-45414: Decidim: JWT-backed authentication can be replayed across organizations

Description A JWT issued to an Org 1 account is accepted on the Org 2 API and can read the admin-only GraphQL participantDetails field for an Org 2 participant. The same trust-boundary problem also affects API-user auth…

8.5CVSS Score

HIGHSeverity

NOCISA KEV

VulnerabilityImpact Type

📋 Vulnerability Details

CVE ID	CVE-2026-45414
Vendor	rubygems
Affected Product	decidim
Vulnerability Type	Vulnerability
CVSS Score	8.5 (HIGH)
Actively Exploited	❌ No known exploitation
Patch Status	See Vendor Advisory →
Reported By	CYBERDUDEBIVASH SENTINEL APEX Intelligence (via github_advisories)

🔬 Technical Analysis

Description A JWT issued to an Org 1 account is accepted on the Org 2 API and can read the admin-only GraphQL `participantDetails` field for an Org 2 participant. The same trust-boundary problem also affects API-user authentication: an Org 1 API user can use a JWT on the Org 1 host and replay that JWT to the Org 2 API to read Org 2 participant personal data and reach Org 2's `proposal.answer` mutation path.

Technical description The current host selects the Decidim organization context, but JWT-backed API authentication is not sufficiently bound to

that host organization. As a result, the API can process a request in Org 2's context while still trusting an authenticated principal from Org 1. Reproduction steps: 1. Use an API key provided by the system administrator that is assigned t

📚 Advisory References

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