Vulnerability-Lookup

CVE-2026-4633 (GCVE-0-2026-4633)

Vulnerability from cvelistv5 – Published: 2026-03-23 10:53 – Updated: 2026-03-23 15:52

Title

Keycloak: keycloak: user enumeration via differential error messages

Summary

A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration.

Severity ?

3.7 (Low)


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

CWE

CWE-209 - Generation of Error Message Containing Sensitive Information

Assigner

redhat

References

URL

Tags

	https://access.redhat.com/security/cve/CVE-2026-4633	vdb-entryx_refsource_REDHAT
	https://bugzilla.redhat.com/show_bug.cgi?id=2450247	issue-trackingx_refsource_REDHAT

Impacted products

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

Date Public ?

2025-03-23 05:05

Show details on NVD website

JSON

To clipboard

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GHSA-RHGQ-F8X5-J2JC

Vulnerability from github – Published: 2026-03-23 12:30 – Updated: 2026-03-26 19:28

Summary

Keycloak's identity-first login flow exposes user information

Details

Severity ?

3.7 (Low)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Maven",
        "name": "org.keycloak:keycloak-services"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "26.5.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-4633"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-209"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-26T19:28:56Z",
    "nvd_published_at": "2026-03-23T11:16:25Z",
    "severity": "LOW"
  },
  "details": "A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration.",
  "id": "GHSA-rhgq-f8x5-j2jc",
  "modified": "2026-03-26T19:28:56Z",
  "published": "2026-03-23T12:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4633"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-4633"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450247"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/keycloak/keycloak"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Keycloak\u0027s  identity-first login flow  exposes user information"
}

FKIE_CVE-2026-4633

Vulnerability from fkie_nvd - Published: 2026-03-23 11:16 - Updated: 2026-03-23 14:31

Severity ?

3.7 (Low) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Summary

References

	URL	Tags
	secalert@redhat.com	https://access.redhat.com/security/cve/CVE-2026-4633
	secalert@redhat.com	https://bugzilla.redhat.com/show_bug.cgi?id=2450247

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in Keycloak. A remote attacker can exploit differential error messages during the identity-first login flow when Organizations are enabled. This vulnerability allows an attacker to determine the existence of users, leading to information disclosure through user enumeration."
    }
  ],
  "id": "CVE-2026-4633",
  "lastModified": "2026-03-23T14:31:37.267",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4,
        "source": "secalert@redhat.com",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-03-23T11:16:25.053",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2026-4633"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450247"
    }
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  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-209"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Primary"
    }
  ]
}

WID-SEC-W-2026-0821

Vulnerability from csaf_certbund - Published: 2026-03-22 23:00 - Updated: 2026-03-26 23:00

Summary

Keycloak: Mehrere Schwachstellen

Severity

Mittel

Notes

Das BSI ist als Anbieter für die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch dafür verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgfältig im Einzelfall zu prüfen.

Produktbeschreibung: Keycloak ermöglicht Single Sign-On mit Identity and Access Management für moderne Anwendungen und Dienste.

Angriff: Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Keycloak ausnutzen, um Sicherheitsvorkehrungen zu umgehen, und um Informationen offenzulegen.

Betroffene Betriebssysteme: - Linux - UNIX

CVE-2026-4628

CVE-2026-4633

References

URL

Category

	https://wid.cert-bund.de/.well-known/csaf/white/2…	self
	https://wid.cert-bund.de/portal/wid/securityadvis…	self
	https://bugzilla.redhat.com/show_bug.cgi?id=2450240	external
	https://bugzilla.redhat.com/show_bug.cgi?id=2450247	external
	https://access.redhat.com/security/cve/cve-2026-4628	external

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "text": "mittel"
    },
    "category": "csaf_base",
    "csaf_version": "2.0",
    "distribution": {
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "de-DE",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "Das BSI ist als Anbieter f\u00fcr die eigenen, zur Nutzung bereitgestellten Inhalte nach den allgemeinen Gesetzen verantwortlich. Nutzerinnen und Nutzer sind jedoch daf\u00fcr verantwortlich, die Verwendung und/oder die Umsetzung der mit den Inhalten bereitgestellten Informationen sorgf\u00e4ltig im Einzelfall zu pr\u00fcfen."
      },
      {
        "category": "description",
        "text": "Keycloak erm\u00f6glicht Single Sign-On mit Identity and Access Management f\u00fcr moderne Anwendungen und Dienste.",
        "title": "Produktbeschreibung"
      },
      {
        "category": "summary",
        "text": "Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Keycloak ausnutzen, um Sicherheitsvorkehrungen zu umgehen, und um Informationen offenzulegen.",
        "title": "Angriff"
      },
      {
        "category": "general",
        "text": "- Linux\n- UNIX",
        "title": "Betroffene Betriebssysteme"
      }
    ],
    "publisher": {
      "category": "other",
      "contact_details": "csaf-provider@cert-bund.de",
      "name": "Bundesamt f\u00fcr Sicherheit in der Informationstechnik",
      "namespace": "https://www.bsi.bund.de"
    },
    "references": [
      {
        "category": "self",
        "summary": "WID-SEC-W-2026-0821 - CSAF Version",
        "url": "https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-0821.json"
      },
      {
        "category": "self",
        "summary": "WID-SEC-2026-0821 - Portal Version",
        "url": "https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-0821"
      },
      {
        "category": "external",
        "summary": "Red Hat Bugtracker vom 2026-03-22",
        "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450240"
      },
      {
        "category": "external",
        "summary": "Red Hat Bugtracker vom 2026-03-22",
        "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450247"
      },
      {
        "category": "external",
        "summary": "Red Hat Security Advisory vom 2026-03-23",
        "url": "https://access.redhat.com/security/cve/cve-2026-4628"
      }
    ],
    "source_lang": "en-US",
    "title": "Keycloak: Mehrere Schwachstellen",
    "tracking": {
      "current_release_date": "2026-03-26T23:00:00.000+00:00",
      "generator": {
        "date": "2026-03-27T09:01:27.904+00:00",
        "engine": {
          "name": "BSI-WID",
          "version": "1.5.0"
        }
      },
      "id": "WID-SEC-W-2026-0821",
      "initial_release_date": "2026-03-22T23:00:00.000+00:00",
      "revision_history": [
        {
          "date": "2026-03-22T23:00:00.000+00:00",
          "number": "1",
          "summary": "Initiale Fassung"
        },
        {
          "date": "2026-03-23T23:00:00.000+00:00",
          "number": "2",
          "summary": "Referenz(en) aufgenommen: EUVD-2026-14389, EUVD-2026-14400"
        },
        {
          "date": "2026-03-26T23:00:00.000+00:00",
          "number": "3",
          "summary": "Referenz(en) aufgenommen: GHSA-RHGQ-F8X5-J2JC"
        }
      ],
      "status": "final",
      "version": "3"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_name",
            "name": "Open Source Keycloak",
            "product": {
              "name": "Open Source Keycloak",
              "product_id": "T052000",
              "product_identification_helper": {
                "cpe": "cpe:/a:keycloak:keycloak:-"
              }
            }
          }
        ],
        "category": "vendor",
        "name": "Open Source"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2026-4628",
      "product_status": {
        "known_affected": [
          "T052000"
        ]
      },
      "release_date": "2026-03-22T23:00:00.000+00:00",
      "title": "CVE-2026-4628"
    },
    {
      "cve": "CVE-2026-4633",
      "product_status": {
        "known_affected": [
          "T052000"
        ]
      },
      "release_date": "2026-03-22T23:00:00.000+00:00",
      "title": "CVE-2026-4633"
    }
  ]
}

Sightings

Author	Source	Type	Date

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

CVE-2026-4633 (GCVE-0-2026-4633)

GHSA-RHGQ-F8X5-J2JC

FKIE_CVE-2026-4633

WID-SEC-W-2026-0821

Tags

Sightings

Nomenclature