How severe is CVE-2026-45414?

CVE-2026-45414 has a CVSS score of 8.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-45414?

CVE-2026-45414 affects the following packages: decidim (RubyGems), decidim (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2026-45414?

Update decidim to 0.31.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45414 is resolved across your whole dependency graph.

How do I detect CVE-2026-45414 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for decidim, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-45414 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2026-45414 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-45414 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-45414?

CVE-2026-45414 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-45414?

CVE-2026-45414 is classified as CWE-639 (CWE-639), CWE-863 (CWE-863). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-45414 published, and has it been updated?

CVE-2026-45414 was published on August 6, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎

💎 RubyGems

Not in CISA KEV

HIGH severity

CVE-2026-45414 — decidim

HIGHFix: decidim/decidim@023e206

CVE-2026-45414 is a high-severity (CVSS 8.5) CWE-639 vulnerability in decidim. A fix is available for decidim — see the affected versions and patch details below.

Decidim: JWT-backed authentication can be replayed across organizations

Also known asGHSA-r3v7-5x4c-c69q

Published

Aug 6, 2026

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-45414.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

💎decidim💎decidim

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

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:

Use an API key provided by the system administrator that is assigned to organization 1 to create the JWT token or get the JWT token shown in the response when logged in as the organization admin.

When using this JWT token it is possible to retrieve details from other organisations. Notice the change of the host header in the request below to that of another tenant org2.localhost:3001

Note that using a participant-generated JWT did not allow showing these results.

Impact

A JWT issued for one organization can be replayed successfully against another organization's API and used to retrieve sensitive details from that organization.

Patches

See https://github.com/decidim/decidim/pull/16673 and https://github.com/decidim/decidim/pull/16756

Workarounds

Disable JWT credentials on system panel (/system)

References

OWASP A01:2021 Broken Access Control

Credits

This issue was discovered in a security audit organized by the Decidim Association and made by Radically Open Security against Decidim financed by NGI.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`decidim`	all versions	0.31.5`bundle update decidim --conservative`
💎RubyGems	`decidim`	≥ 0.32.0.rc1&&< 0.32.0	0.32.0`bundle update decidim --conservative`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for decidim, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update decidim to 0.31.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-45414 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

## 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