CVE-2026-9798: Keycloak services Authentication Bypass Vulnerability
MODERATECVE-2026-9798 is a MODERATE (CVSS 4.3) authentication bypass vulnerability (CWE-305: Authentication Bypass by Primary Weakness) affecting Keycloak services libraries in the Maven ecosystem. The issue involves keycloak has an authentication bypass by primary weakness. Remediation is available in the latest vendor maintenance releases.
CVE-2026-9798 at a Glance
Security Impact
CVSS: 4.3
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N).
How to Fix CVE-2026-9798
To remediate this vulnerability, upgrade all affected Keycloak services dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
<dependency>
<groupId>org.keycloak</groupId>
<artifactId>keycloak-services</artifactId>
<version>Latest secure release</version>
</dependency><dependency>
<groupId>org.keycloak</groupId>
<artifactId>keycloak-services</artifactId>
<version>Latest secure release</version>
</dependency>Run the following command in your project directory to verify that all resolved dependencies use the patched release:
mvn dependency:tree -Dincludes=org.keycloakHow to Check if You Are Affected
To determine whether your Java application is affected by CVE-2026-9798, inspect your build dependencies using the Maven Dependency Plugin:
mvn dependency:tree -Dincludes=org.keycloakAnalyze the terminal output to locate any version of Keycloak services in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.
Note: The mvn dependency:tree -Dincludes=org.keycloak command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-305: Authentication Bypass by Primary Weakness, where the authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error. In Keycloak services, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-9798 Affected Keycloak services Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.keycloak:keycloak-services
|
Maven |
≤ 26.4.7
|
|
|
org.keycloak:keycloak-services
|
Maven |
≥ 26.5.0
≤ 26.6.4
|
|
References
Frequently Asked Questions
What is CVE-2026-9798?
Which Keycloak services versions are affected?
What version fixes CVE-2026-9798?
Is keycloak-services affected?
What is the CVSS score of CVE-2026-9798?
What CWE is associated with CVE-2026-9798?
How can I check Maven dependencies for CVE-2026-9798?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-q6h7-xxp7-7429",
"modified" : "2026-08-05T18:31:21Z",
"published" : "2026-05-28T06:31:09Z",
"aliases" : [ "CVE-2026-9798" ],
"summary" : "Keycloak has an Authentication Bypass by Primary Weakness",
"details" : "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.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.keycloak:keycloak-services"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"last_affected" : "26.4.7"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.keycloak:keycloak-services"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "26.5.0"
}, {
"last_affected" : "26.6.4"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-9798"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/issues/49432"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/pull/49791"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/pull/49903"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/pull/49905"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/11c2695064cd93da1d333df3f69d4a4141e86c29"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/2edc6b112e2dedce63062b89ab3c7ae542e0d9ac"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/a11e3254efc16ae72ce5092b93b9f557a4ba43ae"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:50846"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:50847"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:50848"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:50849"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/security/cve/CVE-2026-9798"
}, {
"type" : "WEB",
"url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2482470"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/keycloak/keycloak"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-305" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-07-01T21:26:22Z",
"nvd_published_at" : "2026-05-28T06:16:29Z"
}
}