# CVE-2024-9666

## Summary

- **CVE ID:** CVE-2024-9666
- **Severity:** MEDIUM
- **CVSS Score:** 4.7 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-444
- **Published:** Nov 25, 2024
- **Last Modified:** Aug 31, 2026

## Description

A vulnerability was found in the Keycloak Server. The Keycloak Server is vulnerable to a denial of service (DoS) attack due to improper handling of proxy headers. When Keycloak is configured to accept incoming proxy headers, it may accept non-IP values, such as obfuscated identifiers, without proper validation. This issue can lead to costly DNS resolution operations, which an attacker could exploit to tie up IO threads and potentially cause a denial of service.
The attacker must have access to send requests to a Keycloak instance that is configured to accept proxy headers, specifically when reverse proxies do not overwrite incoming headers, and Keycloak is configured to trust these headers.

## Affected Products

- Unknown product (0)
- Unknown product (25.0.0)
- Red Hat — Red Hat build of Keycloak 24 (24.0.9-1)
- Red Hat — Red Hat build of Keycloak 24 (24-18)
- Red Hat — Red Hat build of Keycloak 26.0 (26.0.6-2)
- Red Hat — Red Hat build of Keycloak 26.0 (26.0-5)
- Red Hat — Red Hat build of Keycloak 26.0 (26.0-6)

## References

- [CNA](https://access.redhat.com/errata/RHSA-2024:10175)
- [CNA](https://access.redhat.com/errata/RHSA-2024:10176)
- [CNA](https://access.redhat.com/errata/RHSA-2024:10177)
- [CNA](https://access.redhat.com/errata/RHSA-2024:10178)
- [CNA](https://access.redhat.com/security/cve/CVE-2024-9666)
- [CNA](https://bugzilla.redhat.com/show_bug.cgi?id=2317440)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.40%
- **EPSS Percentile:** 34.0

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-19._