# CVE-2026-16108: Keycloak-services: keycloak-services: realm default-group reads disclose hidden groups under fgap v2

> Delegated administrators can view hidden default group names and IDs in Keycloak, exposing sensitive organizational structures.

- **Severity:** Medium 4.3 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Jul 2026
- **Updated:** 16 Sep 2026
- **Also known as:** BIT-keycloak-2026-16108, CLEANSTART-2026-ZE25949, GHSA-mvwh-6438-3v8w

## What is CVE-2026-16108?

CVE-2026-16108 is a medium-severity vulnerability in Redhat Build of Keycloak, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw was found in the default-groups REST endpoint and realm representation of Keycloak. This component is responsible for managing groups that are automatically assigned to new users within a realm. The issue allows a delegated administrator with realm-viewing permissions to see the names and identifiers of hidden default groups, even if they lack the specific permissions to view those groups. This can lead to the exposure of sensitive organizational structures or internal group names.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor), CWE-1220 (Insufficient Granularity of Access Control)

## Which versions are affected by CVE-2026-16108?

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-2026-16108?

Upgrade keycloak to 26.7.3 or later.

## Is CVE-2026-16108 being exploited?

There is no known exploitation of CVE-2026-16108 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-2026-16108 and fix it if it is affected.

What it is: CVE-2026-16108 is a medium-severity vulnerability in Redhat Build of Keycloak, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-16108 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-2026-16108/ (Markdown: https://insights.sbomify.com/CVE-2026-16108/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-16108
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-16108
- OSV: https://osv.dev/vulnerability/CVE-2026-16108

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-16108/
Summaries are generated and may contain mistakes; the official description above is the record.