CVE-2026-1529: Keycloak services Keycloak Affected By Improper Invitation Vulnerability

HIGH
Advisory Identifier: GHSA-hcvw-475w-8g7p
CVSS 8.1
CWE-347
Published
Advisory Summary

CVE-2026-1529 is a HIGH (CVSS 8.1) keycloak affected by improper invitation vulnerability (CWE-347: Improper Verification of Cryptographic Signature) affecting Keycloak services libraries in the Maven ecosystem. The issue involves keycloak affected by improper invitation token validation. Remediation is available by upgrading affected packages to version 26.5.3, 26.2.13, 26.4.9.

CVE-2026-1529 at a Glance

CVE Identifier CVE-2026-1529
GHSA Identifier GHSA-hcvw-475w-8g7p
Severity HIGH
CVSS v3.1 Base Score 8.1
CWE Classification CWE-347: Improper Verification of Cryptographic Signature
Affected Product Keycloak services
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.1

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

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

How to Fix CVE-2026-1529

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.

org.keycloak:keycloak-services fixed: 26.5.3
<dependency>
    <groupId>org.keycloak</groupId>
    <artifactId>keycloak-services</artifactId>
    <version>26.5.3</version>
</dependency>
org.keycloak:keycloak-services fixed: 26.2.13
<dependency>
    <groupId>org.keycloak</groupId>
    <artifactId>keycloak-services</artifactId>
    <version>26.2.13</version>
</dependency>
org.keycloak:keycloak-services fixed: 26.4.9
<dependency>
    <groupId>org.keycloak</groupId>
    <artifactId>keycloak-services</artifactId>
    <version>26.4.9</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-2026-1529, 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 services in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 26.5.3), 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-347: Improper Verification of Cryptographic Signature, where the product does not verify, or incorrectly verifies, the cryptographic signature for data. 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

A flaw was found in Keycloak. An attacker can exploit this vulnerability by modifying the organization ID and target email within a legitimate invitation token's JSON Web Token (JWT) payload. This lack of cryptographic signature verification allows the attacker to successfully self-register into an unauthorized organization, leading to unauthorized access.

CVE-2026-1529 Affected Keycloak services Versions

3 component(s)
Fixed Versions:
26.5.326.2.1326.4.9
Product / Package Ecosystem Affected Versions Fixed Version
org.keycloak:keycloak-services
Maven
≥ 26.5.0
< 26.5.3
26.5.3
org.keycloak:keycloak-services
Maven
< 26.2.13
26.2.13
org.keycloak:keycloak-services
Maven
≥ 26.3.0
< 26.4.9
26.4.9

References

Frequently Asked Questions

What is CVE-2026-1529?
CVE-2026-1529 is a security vulnerability in Keycloak services involving Keycloak affected by improper invitation token validation under CWE-347: Improper Verification of Cryptographic Signature.
Which Keycloak services versions are affected?
Affected versions include releases prior to 26.5.3, 26.2.13, 26.4.9 across affected packages: org.keycloak:keycloak-services.
What version fixes CVE-2026-1529?
Upgrading to 26.5.3, 26.2.13, 26.4.9 (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 26.5.3, 26.2.13, 26.4.9. Upgrade your dependency to 26.5.3, 26.2.13, 26.4.9 or later.
What is the CVSS score of CVE-2026-1529?
CVE-2026-1529 has a CVSS v3.1 base score of 8.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2026-1529?
CVE-2026-1529 is classified under CWE-347: Improper Verification of Cryptographic Signature (The product does not verify, or incorrectly verifies, the cryptographic signature for data.).
How can I check Maven dependencies for CVE-2026-1529?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-hcvw-475w-8g7p",
  "modified" : "2026-02-13T20:32:01Z",
  "published" : "2026-02-09T21:31:03Z",
  "aliases" : [ "CVE-2026-1529" ],
  "summary" : "Keycloak affected by improper invitation token validation",
  "details" : "A flaw was found in Keycloak. An attacker can exploit this vulnerability by modifying the organization ID and target email within a legitimate invitation token's JSON Web Token (JWT) payload. This lack of cryptographic signature verification allows the attacker to successfully self-register into an unauthorized organization, leading to unauthorized access.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.keycloak:keycloak-services"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "26.5.0"
      }, {
        "fixed" : "26.5.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.keycloak:keycloak-services"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "26.2.13"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.keycloak:keycloak-services"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "26.3.0"
      }, {
        "fixed" : "26.4.9"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-1529"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/issues/46145"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/pull/46155"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/commit/82cd7941d1dd28fa14a67a6e6b912301f1a5e1a1"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/commit/8fc9a98026106a326f4faa98d4c9a48341ace2d7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/keycloak/keycloak/commit/b2519756487b519f95c07aa8b10afe003e492119"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:2363"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:2364"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:2365"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/errata/RHSA-2026:2366"
  }, {
    "type" : "WEB",
    "url" : "https://access.redhat.com/security/cve/CVE-2026-1529"
  }, {
    "type" : "WEB",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2433783"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/keycloak/keycloak"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-347" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-10T18:35:20Z",
    "nvd_published_at" : "2026-02-09T20:15:55Z"
  }
}