CVE-2026-9084

What it is

MISP’s OIDC authentication plugin allowed automatic linking of an OIDC identity to an existing local user account based on the email claim when the local account had no stored sub value. Under insecure or untrusted IdP configurations where email ownership is not enforced, an attacker with a valid OIDC token could assert a victim’s email address and authenticate as that user, leading to account takeover.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. High risk of data exposure.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-20 16:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-23 12:10 UTC Last updatedMost recent change to the record

Details

Published

2026-05-20 16:16 UTC

Last modified

2026-07-23 12:10 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-287 · Improper authentication

Record status

Awaiting Analysis

Attack profile CVSS 4.0 · 6.0

Attack vector

Adjacent network

Complexity

High

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

None

Availability

None