Vulnerability-Lookup

GHSA-CPF7-J4CF-VQX4

Vulnerability from github – Published: 2026-05-28 06:31 – Updated: 2026-05-28 06:31

Details

A flaw was found in Keycloak's ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed 'Authorization: Bearer' header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.

Severity

5.3 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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JSON

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  ],
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    "cwe_ids": [
      "CWE-125"
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    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-28T06:16:29Z",
    "severity": "MODERATE"
  },
  "details": "A flaw was found in Keycloak\u0027s ClientRegistrationAuth component. A remote unauthenticated attacker can exploit this vulnerability by sending a specially crafted POST request with a malformed \u0027Authorization: Bearer\u0027 header to any client registration endpoint. This can lead to an ArrayIndexOutOfBoundsException, causing the server to return an HTTP 500 error and resulting in a Denial of Service (DoS) for the affected service.",
  "id": "GHSA-cpf7-j4cf-vqx4",
  "modified": "2026-05-28T06:31:10Z",
  "published": "2026-05-28T06:31:10Z",
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    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-9803"
    },
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      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-9803"
    },
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      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2482465"
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      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-9803 (GCVE-0-2026-9803)

Vulnerability from cvelistv5 – Published: 2026-05-28 04:47 – Updated: 2026-05-28 13:10

Title

Keycloak: keycloak: denial of service via malformed authorization header

Summary

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-125 - Out-of-bounds Read

Assigner

redhat

References

2 references

URL	Tags
https://access.redhat.com/security/cve/CVE-2026-9803	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2482465	issue-trackingx_refsource_REDHAT

Impacted products

1 product

Vendor	Product	Version
Red Hat	Red Hat Build of Keycloak	cpe:/a:redhat:build_keycloak:

Date Public

2026-05-28 04:03

Credits

Red Hat would like to thank Mustafa Çetin for reporting this issue.

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JSON

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                  },
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                "timestamp": "2026-05-28T13:09:44.442993Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-CPF7-J4CF-VQX4

CVE-2026-9803 (GCVE-0-2026-9803)

Tags

Sightings

Nomenclature