# CVE-2026-1609: Org.keycloak/keycloak-quarkus-server: keycloak: unauthorized access via jwt authorization grant with disabled users

> Attackers can bypass authentication for disabled users via JWT grants when the preview feature is enabled, gaining unauthorized access to sensitive resources.

- **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:** 16 Jul 2026
- **Updated:** 10 Aug 2026
- **Also known as:** BIT-keycloak-2026-1609, GHSA-5xcf-8m2w-ph6f

## What is CVE-2026-1609?

CVE-2026-1609 is a high-severity authentication bypass vulnerability in Redhat Build of Keycloak, published on 16 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 Keycloak. When the JSON Web Token (JWT) authorization grant preview feature is enabled and a user account is disabled, Keycloak fails to validate the user’s disabled status during JWT authorization grant processing. A remote attacker with low privileges can exploit this improper access control vulnerability by presenting a valid assertion token from an external identity provider to obtain a JWT for a disabled user. This allows unauthorized access to sensitive resources.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-1609?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `keycloak` | Bitnami | From 26.5.2 | 26.5.3 |

Products: Redhat Build of Keycloak.

## How do I fix CVE-2026-1609?

Upgrade keycloak to 26.5.3 or later.

## Is CVE-2026-1609 being exploited?

There is no known exploitation of CVE-2026-1609 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-2026-11800](https://insights.sbomify.com/CVE-2026-11800/): Org.keycloak:keycloak-services: keycloak: authentication bypass via jwt algorithm confusion (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-1609 and fix it if it is affected.

What it is: CVE-2026-1609 is a high-severity authentication bypass vulnerability in Redhat Build of Keycloak, published on 16 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-2026-1609 in the wild and no public exploit code.

Affected packages and fixed versions:
- keycloak (Bitnami): affected from 26.5.2; fixed in 26.5.3

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-2026-1609/ (Markdown: https://insights.sbomify.com/CVE-2026-1609/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-1609
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-1609
- OSV: https://osv.dev/vulnerability/CVE-2026-1609

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-1609/
Summaries are generated and may contain mistakes; the official description above is the record.