CVE-2026-37980: Keycloak Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-m32f-8vh9-2hh3
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CVSS 6.9
CWE-79
Published
Advisory Summary

CVE-2026-37980 is a MODERATE (CVSS 6.9) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Keycloak libraries in the Maven ecosystem. The issue involves arbitrary code execution via stored cross-site scripting (xss) in organization selection login page. Remediation is available in the latest vendor maintenance releases.

CVE-2026-37980 at a Glance

CVE Identifier CVE-2026-37980
GHSA Identifier GHSA-m32f-8vh9-2hh3
Severity MODERATE
CVSS v3.1 Base Score 6.9
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Keycloak
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 6.9

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity Low (I:L)
Availability None (A:N)

How to Fix CVE-2026-37980

To remediate this vulnerability, upgrade all affected Keycloak dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

org.keycloak:keycloak-services fixed: Latest secure release 
<dependency>
    <groupId>org.keycloak</groupId>
    <artifactId>keycloak-services</artifactId>
    <version>Latest secure release</version>
</dependency>
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree -Dincludes=org.keycloak

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-37980, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree -Dincludes=org.keycloak

Analyze the terminal output to locate any version of Keycloak 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-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Keycloak, 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

A flaw was found in Keycloak, specifically in the organization selection login page. A remote attacker with `manage-realm` or `manage-organizations` administrative privileges can exploit a Stored Cross-Site Scripting (XSS) vulnerability. This flaw occurs because the `organization.alias` is placed into an inline JavaScript `onclick` handler, allowing a crafted JavaScript payload to execute in a user's browser when they view the login page. Successful exploitation enables arbitrary JavaScript execution, potentially leading to session theft, unauthorized account actions, or further attacks against users of the affected realm.

CVE-2026-37980 Affected Keycloak Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
org.keycloak:keycloak-services
maven/org.keycloak/keycloak-services
Maven
≤ 26.5.5

References

NVD — CVE-2026-37980 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-37980
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak/issues/48049
Keycloak Security Information SECURITY
https://access.redhat.com/security/cve/CVE-2026-37980
bugzilla.redhat.com/show_bug.cgi WEB
https://bugzilla.redhat.com/show_bug.cgi?id=2455325
Keycloak Source Repository REPOSITORY
https://github.com/keycloak/keycloak

Frequently Asked Questions

What is CVE-2026-37980?
CVE-2026-37980 is a security vulnerability in Keycloak involving Arbitrary code execution via Stored Cross-Site Scripting (XSS) in organization selection login page under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Keycloak versions are affected?
Affected versions include releases prior to current release patches across affected packages: org.keycloak:keycloak-services.
What version fixes CVE-2026-37980?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is keycloak-services affected?
Yes, org.keycloak:keycloak-services is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-37980?
CVE-2026-37980 has a CVSS v3.1 base score of 6.9 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N.
What CWE is associated with CVE-2026-37980?
CVE-2026-37980 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Maven dependencies for CVE-2026-37980?
Run the dependency tree command: 'mvn dependency:tree -Dincludes=org.keycloak'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m32f-8vh9-2hh3",
  "modified" : "2026-04-16T01:34:56Z",
  "published" : "2026-04-14T15:30:35Z",
  "aliases" : [ "CVE-2026-37980" ],
  "summary" : "Keycloak: Arbitrary code execution via Stored Cross-Site Scripting (XSS) in organization selection login page",
  "details" : "A flaw was found in Keycloak, specifically in the organization selection login page. A remote attacker with `manage-realm` or `manage-organizations` administrative privileges can exploit a Stored Cross-Site Scripting (XSS) vulnerability. This flaw occurs because the `organization.alias` is placed into an inline JavaScript `onclick` handler, allowing a crafted JavaScript payload to execute in a user's browser when they view the login page. Successful exploitation enables arbitrary JavaScript execution, potentially leading to session theft, unauthorized account actions, or further attacks against users of the affected realm.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.keycloak:keycloak-services"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "26.5.5"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-37980"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/issues/48049"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-37980"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2455325"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/keycloak/keycloak"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-16T01:34:56Z",
    "nvd_published_at" : "2026-04-14T15:16:34Z"
  }
}