# CVE-2026-0871: Org.keycloak/keycloak-services: keycloak: unauthorized modification of unmanaged user attributes by administrators

> Administrators can bypass restrictions to modify unmanaged user attributes, leading to unauthorized profile changes in Keycloak deployments.

- **Severity:** Medium 4.9 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 27 Feb 2026
- **Updated:** 6 Mar 2026
- **Also known as:** BIT-keycloak-2026-0871, ECHO-738b-62c7-508f, GHSA-v4jw-m6rm-399h, MINI-mhh6-r3xq-h4c4, MINI-rpvp-r4gf-cgxh

## What is CVE-2026-0871?

CVE-2026-0871 is a medium-severity missing authorization vulnerability in Redhat Build of Keycloak, published on 27 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A flaw was found in Keycloak. An administrator with `manage-users` permission can bypass the "Only administrators can view" setting for unmanaged attributes, allowing them to modify these attributes. This improper access control can lead to unauthorized changes to user profiles, even when the system is configured to restrict such modifications.

Weakness: CWE-266 (Incorrect Privilege Assignment)

## Which versions are affected by CVE-2026-0871?

3 open source packages ship an affected version, including org.keycloak:keycloak-server-spi-private and keycloak. It affects 2 products.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.keycloak:keycloak-server-spi-private` | Maven | All versions | 26.5.2 |
| `org.keycloak:keycloak-server-spi-private` | Maven | All versions | 26.5.2 |
| `keycloak` | Bitnami | All versions | 26.4.9 |

Products: Redhat Build of Keycloak, Redhat Keycloak.

## How do I fix CVE-2026-0871?

Upgrade org.keycloak:keycloak-server-spi-private to 26.5.2 or later.

## Is CVE-2026-0871 being exploited?

There is no known exploitation of CVE-2026-0871 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-2026-0871 and fix it if it is affected.

What it is: CVE-2026-0871 is a medium-severity missing authorization vulnerability in Redhat Build of Keycloak, published on 27 Feb 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-0871 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.keycloak:keycloak-server-spi-private (Maven): affected all versions; fixed in 26.5.2
- org.keycloak:keycloak-server-spi-private (Maven): affected all versions; fixed in 26.5.2
- keycloak (Bitnami): affected all versions; fixed in 26.4.9

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-2026-0871/ (Markdown: https://insights.sbomify.com/CVE-2026-0871/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0871
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0871
- OSV: https://osv.dev/vulnerability/CVE-2026-0871

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0871/
Summaries are generated and may contain mistakes; the official description above is the record.