# CVE-2026-9689: Keycloak Services has Improper Validation of Consistency within Input

> Attackers can bypass security measures and gain unauthorized access via HTTP parameter pollution in OIDC redirect URIs when broad URIs are configured.

- **Severity:** Medium 4.2 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 27 May 2026
- **Updated:** 20 Aug 2026
- **Also known as:** ECHO-6280-5637-dd2f, GHSA-wcvj-vpvw-9rr5, MINI-78hg-7xf7-9cj7, MINI-7r7v-98hv-q3jv

## What is CVE-2026-9689?

CVE-2026-9689 is a medium-severity authentication bypass vulnerability in Redhat Build of Keycloak, published on 27 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

A flaw was found in Keycloak, an open-source identity and access management solution. When a client application is configured to accept broad redirect Uniform Resource Identifiers (URIs), a remote attacker can manipulate the authentication process by crafting a special web address. If a user clicks this link, the client application might incorrectly prioritize attacker-controlled information over legitimate data. This vulnerability, known as HTTP parameter pollution, could allow an attacker to bypass security measures or gain unauthorized access to resources.

Weakness: CWE-1288 (Improper Validation of Consistency within Input)

## Which versions are affected by CVE-2026-9689?

4 open source packages ship an affected version, including org.keycloak:keycloak-services. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `org.keycloak:keycloak-services` | Maven | All versions to 26.4.7 | None |
| `org.keycloak:keycloak-services` | Maven | All versions to 26.4.7 | None |
| `org.keycloak:keycloak-services` | Maven | From 26.5.0 to 26.6.4 | None |
| `org.keycloak:keycloak-services` | Maven | From 26.5.0 to 26.6.4 | None |

Products: Redhat Build of Keycloak.

## How do I fix CVE-2026-9689?

Upgrade to a fixed version.

## Is CVE-2026-9689 being exploited?

There is no known exploitation of CVE-2026-9689 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-2026-9689 and fix it if it is affected.

What it is: CVE-2026-9689 is a medium-severity authentication bypass vulnerability in Redhat Build of Keycloak, published on 27 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-9689 in the wild and no public exploit code.

Affected packages and fixed versions:
- org.keycloak:keycloak-services (Maven): affected all versions up to 26.4.7; no fix listed
- org.keycloak:keycloak-services (Maven): affected all versions up to 26.4.7; no fix listed
- org.keycloak:keycloak-services (Maven): affected from 26.5.0 up to 26.6.4; no fix listed
- org.keycloak:keycloak-services (Maven): affected from 26.5.0 up to 26.6.4; no fix listed

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-2026-9689/ (Markdown: https://insights.sbomify.com/CVE-2026-9689/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-9689
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-9689
- OSV: https://osv.dev/vulnerability/CVE-2026-9689

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-9689/
Summaries are generated and may contain mistakes; the official description above is the record.