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.
History

Wed, 20 May 2026 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Misp
Misp misp
Vendors & Products Misp
Misp misp

Wed, 20 May 2026 16:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 20 May 2026 15:30:00 +0000

Type Values Removed Values Added
Description 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.
Title MISP OIDC authentication bypass via automatic email-based account linking under insecure IdP configurations
Weaknesses CWE-287
References
Metrics cvssV4_0

{'score': 6, 'vector': 'CVSS:4.0/AV:A/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-05-20T15:28:55.640Z

Reserved: 2026-05-20T14:21:56.589Z

Link: CVE-2026-9084

cve-icon Vulnrichment

Updated: 2026-05-20T15:28:52.979Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-20T16:16:28.107

Modified: 2026-05-20T17:31:45.303

Link: CVE-2026-9084

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-20T16:30:14Z