# CVE-2026-9798 — Red Hat build of Keycloak 26.4

> As of 2026-08-20, CVE-2026-9798 is a MEDIUM-severity vulnerability in Red Hat build of Keycloak 26.4, CVSS v3.1 4.3, EPSS 0.4% (40.2th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-9798, most recently “CVE-2026-17059: Keycloak Admin REST API Broken Object-Level Authorization Exposes User PII”.

**Last updated:** 2026-08-20

## What is CVE-2026-9798?

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.

The record classifies CVE-2026-9798 under weakness class [CWE-305](https://intel.threadlinqs.com/cwe/CWE-305). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 4 affected-product entries are recorded, across 1 vendor, listed below. The identifier was first published 153 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 4.3 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N`)
- **EPSS (FIRST):** 0.4% probability of exploitation in the next 30 days, higher than 40.2% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.8/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-05-28, last modified 2026-08-20

## Is CVE-2026-9798 being exploited?

It currently carries a trending score of 15 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Red Hat](https://intel.threadlinqs.com/vendors/red-hat): build of Keycloak 26.4, build of Keycloak 26.4.14, build of Keycloak 26.6, build of Keycloak 26.6.5

Affected software packages:

- `maven:org.keycloak:keycloak-services`
- `maven:org.keycloak:keycloak-services`

## How to fix CVE-2026-9798

No vendor patch reference has been recorded for CVE-2026-9798 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-9798

1 tracked threat in the Threadlinqs corpus references CVE-2026-9798, either in the campaign’s CVE list or as an indicator on the campaign record.

- [CVE-2026-17059: Keycloak Admin REST API Broken Object-Level Authorization Exposes User PII](https://intel.threadlinqs.com/threat/TL-2026-1796) — MEDIUM · 2026-07-31

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Vendor advisory and patch**

- [access.redhat.com — vendor advisory](https://access.redhat.com/errata/RHSA-2026:50846)
- [access.redhat.com — vendor advisory (RHSA 2026:50847)](https://access.redhat.com/errata/RHSA-2026:50847)
- [access.redhat.com — vendor advisory (RHSA 2026:50848)](https://access.redhat.com/errata/RHSA-2026:50848)
- [access.redhat.com — vendor advisory (RHSA 2026:50849)](https://access.redhat.com/errata/RHSA-2026:50849)

**Third-party advisory**

- [access.redhat.com — vdb entry](https://access.redhat.com/security/cve/CVE-2026-9798)
- [bugzilla.redhat.com — issue tracking](https://bugzilla.redhat.com/show_bug.cgi?id=2482470)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-9798
Full detection coverage and IOCs for threats exploiting CVE-2026-9798 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp