CVE-2026-16103

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 59/100
Published: 2026-07-17 Modified: 2026-11-06 First seen: 2026-11-06 Status: active

Attack Surface

Network Low Complexity No Auth

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Required
S: Unchanged
C: Low
I: None
A: None

Description

A flaw was found in the keycloak-services component of Keycloak. This issue is an incomplete fix for CVE-2026-9798, where brute-force protection checks were added to the Client-Initiated Backchannel Authentication (CIBA) initiation handler but were omitted from the token redemption handler. This allows an attacker with valid client credentials to obtain access and refresh tokens for a user account that has been locked due to brute-force protection, provided the authentication request was started before the lockout occurred and was approved by the user.

Affected Software (1)

VendorProductVersion
redhat build_of_keycloak -

References & Advisories (4)

https://access.redhat.com/errata/RHSA-2026:95761
vendor-advisory x_refsource_REDHAT
https://access.redhat.com/errata/RHSA-2026:95762
vendor-advisory x_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2501736
issue-tracking x_refsource_REDHAT

Bug Bounty Relevance

59 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

4.3 / 10.0 v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

EPSS — Exploitation Probability

0.44%
Raw Score 0.004370
Percentile 38.5%
Date 2026-11-13

EPSS Trend

2026-11-13
0.00437
2026-11-12
0.00437
2026-11-10
0.00437
2026-11-09
0.00437
2026-11-08
0.00437
2026-11-07
0.00437
2026-11-06
0.00345
2026-11-05
0.00345

Intelligence Sources

mitre ref →
nvd ref →