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Fencer Vulns
medium 4.7

CVE-2024-9666 json

Org.keycloak/keycloak-quarkus-server: keycloak proxy header handling denial-of-service (dos) vulnerability

published 2024-11-25 23 mo ago modified 2026-11-03 5 d ago also GHSA-jgwc-jh89-rpgq , EUVD-2024-3365

cvss
4.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.keycloak:keycloak-quarkus-server 26.0.6
  • Red Hat Red Hat build of Keycloak 24 24-18, 24.0.9-1
  • Red Hat Red Hat build of Keycloak 26.0 26.0-5, 26.0-6, 26.0.6-2

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-9666 updated cvss 4.7

org.keycloak/keycloak-quarkus-server: Keycloak proxy header handling Denial-of-Service (DoS) vulnerability

  • Red Hat Build of Keycloak keycloak-quarkus-server
    affected: workaround, no fix available “Fix deferred”
  • Red Hat build of Keycloak 24 rhbk/keycloak-rhel9 24-18, rhbk/keycloak-rhel9-operator 24-18, rhbk/keycloak-operator-bundle 24.0.9-1
    fixed: vendor fix RHSA-2024:10175
  • Red Hat build of Keycloak 24.0.9
    fixed: vendor fix RHSA-2024:10176
  • Red Hat build of Keycloak 26.0 rhbk/keycloak-rhel9 26.0-5, rhbk/keycloak-rhel9-operator 26.0-6, rhbk/keycloak-operator-bundle 26.0.6-2
    fixed: vendor fix RHSA-2024:10177
  • Red Hat build of Keycloak 26.0.6
    fixed: vendor fix RHSA-2024:10178
  • Red Hat JBoss Enterprise Application Platform 8 keycloak-quarkus-server
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
23 mo ago

Exploit prediction

0.40% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven org.keycloak:keycloak-quarkus-server
all versions
>=25.0.0, <26.0.6
26.0.6

Affected products

  • Red Hat Red Hat build of Keycloak 24
  • Red Hat Red Hat build of Keycloak 24.0.9
  • Red Hat Red Hat build of Keycloak 26.0
  • Red Hat Red Hat build of Keycloak 26.0.6
  • Red Hat Red Hat Build of Keycloak
  • Red Hat Red Hat JBoss Enterprise Application Platform 8

Classification

Weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests

References

Sources

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