CVE-2026-4874: Keycloak services Keycloak Server-Side Request Forgery Vulnerability
LOWCVE-2026-4874 is a LOW (CVSS 3.1) keycloak server-side request forgery vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Keycloak services libraries in the Maven ecosystem. The issue involves keycloak server-side request forgery via oidc token endpoint manipulation. Remediation is available by upgrading affected packages to version 26.6.3, 26.4.13.
CVE-2026-4874 at a Glance
Security Impact
CVSS: 3.1
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N).
How to Fix CVE-2026-4874
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>26.6.3</version>
</dependency><dependency>
<groupId>org.keycloak</groupId>
<artifactId>keycloak-services</artifactId>
<version>26.4.13</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-2026-4874, 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 26.6.3), 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-918: Server-Side Request Forgery (SSRF), where the web server receives a url or similar request from an upstream component and retrieves the contents of this url, but it does not sufficiently ensure that the request is being sent to the expected destination. 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-2026-4874 Affected Keycloak services Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
org.keycloak:keycloak-services
|
Maven |
≥ 26.5.0
< 26.6.3
|
26.6.3
|
|
org.keycloak:keycloak-services
|
Maven |
< 26.4.13
|
26.4.13
|
References
Frequently Asked Questions
What is CVE-2026-4874?
Which Keycloak services versions are affected?
What version fixes CVE-2026-4874?
Is keycloak-services affected?
What is the CVSS score of CVE-2026-4874?
What CWE is associated with CVE-2026-4874?
How can I check Maven dependencies for CVE-2026-4874?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-22rm-wp4x-v5cx",
"modified" : "2026-07-15T20:11:33Z",
"published" : "2026-03-26T09:30:28Z",
"aliases" : [ "CVE-2026-4874" ],
"summary" : "Keycloak Server-Side Request Forgery via OIDC token endpoint manipulation",
"details" : "A flaw was found in Keycloak. An authenticated attacker can perform Server-Side Request Forgery (SSRF) by manipulating the `client_session_host` parameter during refresh token requests. This occurs when a Keycloak client is configured to use the `backchannel.logout.url` with the `application.session.host` placeholder. Successful exploitation allows the attacker to make HTTP requests from the Keycloak server’s network context, potentially probing internal networks or internal APIs, leading to information disclosure.",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Maven",
"name" : "org.keycloak:keycloak-services"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "26.5.0"
}, {
"fixed" : "26.6.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Maven",
"name" : "org.keycloak:keycloak-services"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "26.4.13"
} ]
} ]
} ],
"references" : [ {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-4874"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/issues/47935"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/pull/49682"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/pull/49685"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/00dd0dd716c4319d3bac3eb2f2ac22d2a94f79fd"
}, {
"type" : "WEB",
"url" : "https://github.com/keycloak/keycloak/commit/63de0efd351a7a684212a042a12271908f63f0ee"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:25097"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:25098"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:30049"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/errata/RHSA-2026:30050"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/security/cve/CVE-2026-4874"
}, {
"type" : "WEB",
"url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2451611"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/keycloak/keycloak"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-918" ],
"severity" : "LOW",
"github_reviewed" : true,
"github_reviewed_at" : "2026-03-27T20:03:17Z",
"nvd_published_at" : "2026-03-26T08:16:22Z"
}
}