CVE-2026-9798

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 59/100
Published: 2026-05-28 Modified: 2026-10-26 First seen: 2026-10-29 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 Keycloak, an open-source identity and access management solution. When a user account is temporarily locked due to repeated failed login attempts, an attacker with valid client credentials can exploit the Client-Initiated Backchannel Authentication (CIBA) flow to bypass this brute-force protection. This allows continued authentication attempts and token issuance even when the account should be locked, potentially enabling further unauthorized access attempts.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
redhat build_of_keycloak -

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

0.38%
Raw Score 0.003750
Percentile 31.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00375
2026-10-28
0.00375

Intelligence Sources

nvd ref →