# CVE-2026-1529: Keycloak improper signature verification in organization invitations

Source: https://junglewise.ai/threats/cve-2026-1529-keycloak-improper-signature-verification-in-organization  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-02-09. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-1529 · Severity: high · CVSS 8.1 · Published 2026-02-09

Keycloak, a popular identity and access management tool, contains a security flaw in how it handles organization invitations. An attacker can modify a legitimate invitation to gain unauthorized access to organizations they were not invited to. This could allow unauthorized users to register themselves within sensitive corporate environments, potentially leading to data exposure or further unauthorized actions.

Technologies: [org.keycloak:keycloak-services (Maven)](https://junglewise.ai/threats/technologies/org-keycloak-keycloak-services), [Red Hat build of Keycloak](https://junglewise.ai/threats/technologies/red-hat-build-of-keycloak). Vendors: [Maven](https://junglewise.ai/threats/vendors/maven), [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-1529 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-1529 being exploited in the wild.

**How severe is CVE-2026-1529?** High severity, with a CVSS score of 8.1, published 9 February 2026.

**Which products and versions are affected?** org.keycloak:keycloak-services (Maven) ECOSYSTEM:introduced=26.5.0,fixed=26.5.3; Red Hat build of Keycloak 26.2, 26.4, versions prior to 26.2.13 and 26.4.9.

**Is there a fix for CVE-2026-1529?** Yes. org.keycloak:keycloak-services (Maven): upgrade to 26.5.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-1529 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-1529?** Check whether you run org.keycloak:keycloak-services (Maven) or Red Hat build of Keycloak at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.keycloak:keycloak-services (Maven): upgrade to 26.5.3 or later

  ```sh
  # set org.keycloak:keycloak-services to 26.5.3 in your pom.xml or build.gradle
  ```


## Technical details

A vulnerability exists in Keycloak due to improper verification of cryptographic signatures (CWE-347) within JSON Web Token (JWT) payloads used for organization invitations. An attacker with a legitimate invitation token can modify the organization ID and target email address within the payload. Because the system fails to properly validate the signature after these modifications, the attacker can successfully self-register into an unauthorized organization. This flaw requires network access and low-level authentication (possession of a valid token) to exploit. Red Hat has released patches in versions 26.2.13 and 26.4.9 to address this issue.

## Affected products

- Red Hat Red Hat build of Keycloak 26.2, 26.4, versions prior to 26.2.13 and 26.4.9

## Identifiers

- CVE-2026-1529
- GHSA-hcvw-475w-8g7p

## Timeline

- 2026-02-09: disclosed
- 2026-02-09: patched: Fixed in Red Hat build of Keycloak 26.2.13 and 26.4.9

## References

- [https://catalog.redhat.com/software/containers/](https://catalog.redhat.com/software/containers/)
- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/errata/RHSA-2026:2363](https://access.redhat.com/errata/RHSA-2026:2363)
- [https://access.redhat.com/errata/RHSA-2026:2364](https://access.redhat.com/errata/RHSA-2026:2364)
- [https://access.redhat.com/errata/RHSA-2026:2365](https://access.redhat.com/errata/RHSA-2026:2365)
- [https://access.redhat.com/errata/RHSA-2026:2366](https://access.redhat.com/errata/RHSA-2026:2366)
- [https://access.redhat.com/security/cve/CVE-2026-1529](https://access.redhat.com/security/cve/CVE-2026-1529)

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- [Keycloak keycloak-services improper wildcard domain validation in client policies](https://junglewise.ai/threats/cve-2026-18206-keycloak-keycloak-services-improper-wildcard-domain-validation-in)
- [Keycloak keycloak-services authorization bypass in role-users endpoint](https://junglewise.ai/threats/cve-2026-17059-keycloak-keycloak-services-authorization-bypass-in-role-users)
- [Red Hat Keycloak authorization bypass in FGAP v2 child group endpoint](https://junglewise.ai/threats/cve-2026-14615-red-hat-keycloak-authorization-bypass-in-fgap-v2-child-group)