# CVE-2026-18571: Keycloak-services: keycloak-services: fgap v2 group assignment bypass during user creation

> Sub-administrators can bypass group restrictions during user creation, granting unauthorized group memberships and potential privilege escalation.

- **Severity:** Medium 6.6 (`CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 2 Aug 2026
- **Updated:** 16 Sep 2026
- **Also known as:** BIT-keycloak-2026-18571, CLEANSTART-2026-MZ50851, GHSA-5vmc-qhfj-qxc3

## What is CVE-2026-18571?

CVE-2026-18571 is a medium-severity missing authorization vulnerability in Redhat Build of Keycloak, published on 2 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A flaw was found in the user creation component of Keycloak when Fine-Grained Admin Permissions V2 (FGAP V2) is enabled. This issue allows a sub-administrator with permission to create users to add those users to any group, even groups the sub-administrator is not authorized to manage. This could lead to unauthorized access to sensitive information or elevated privileges for the newly created users.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-18571?

1 open source package ship an affected version, including keycloak. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `keycloak` | Bitnami | All versions | 26.7.3 |

Products: Redhat Build of Keycloak.

## How do I fix CVE-2026-18571?

Upgrade keycloak to 26.7.3 or later.

## Is CVE-2026-18571 being exploited?

There is no known exploitation of CVE-2026-18571 in the wild and no public exploit code.

## Other vulnerabilities in Redhat Build of Keycloak

- [CVE-2026-15572](https://insights.sbomify.com/CVE-2026-15572/): Keycloak-services: keycloak-services: dcr protocol mapper type-swap policy bypass allows privilege escalation (high 8.8)
- [CVE-2026-3047](https://insights.sbomify.com/CVE-2026-3047/): Keycloak SAML Broken has Authentication Bypass by Primary Weakness (high 8.8)
- [CVE-2026-15573](https://insights.sbomify.com/CVE-2026-15573/): Keycloak-services: keycloak-services: authorization bypass via unnormalized uri matching in pathmatcher (high 8.1)
- [CVE-2026-16102](https://insights.sbomify.com/CVE-2026-16102/): Keycloak-services: keycloak-services: default dcr policy allows role forgery via user property mappers (high 8.1)
- [CVE-2026-1609](https://insights.sbomify.com/CVE-2026-1609/): Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-18571 and fix it if it is affected.

What it is: CVE-2026-18571 is a medium-severity missing authorization vulnerability in Redhat Build of Keycloak, published on 2 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-18571 in the wild and no public exploit code.

Affected packages and fixed versions:
- keycloak (Bitnami): affected all versions; fixed in 26.7.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-18571/ (Markdown: https://insights.sbomify.com/CVE-2026-18571/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-18571
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-18571
- OSV: https://osv.dev/vulnerability/CVE-2026-18571

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-18571/
Summaries are generated and may contain mistakes; the official description above is the record.