CVE-2026-109082

medium

Description

A flaw was found in the Client-Initiated Backchannel Authentication CIBA implementation within the keycloak-services component of Keycloak. This component handles advanced authentication flows where a client initiates a login on behalf of a user. The issue occurs because Keycloak fails to verify that a client is authorized to use the CIBA flow, allowing public clients to bypass security requirements. An attacker could use this flaw to trick a user into approving a login request, eventually gaining full access to the users account without needing a client secret.

References

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-97260

https://bugzilla.redhat.com/show_bug.cgi?id=2549478

https://access.redhat.com/security/cve/CVE-2026-109082

Details

Source: Mitre, NVD

Published: 2026-10-12

Updated: 2026-10-15

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 6.8

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Severity: Medium

EPSS

EPSS: 0.00248