Vulnerability-Lookup

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

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

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{
  "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"
}

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

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

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  "containers": {
    "adp": [
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        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-4633",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-23T15:07:15.419255Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-03-23T15:52:36.681Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:"
          ],
          "defaultStatus": "affected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat Build of Keycloak",
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      "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."
        }
      ],
      "metrics": [
        {
          "other": {
            "content": {
              "namespace": "https://access.redhat.com/security/updates/classification/",
              "value": "Low"
            },
            "type": "Red Hat severity rating"
          }
        },
        {
          "cvssV3_1": {
            "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",
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          },
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              "description": "Generation of Error Message Containing Sensitive Information",
              "lang": "en",
              "type": "CWE"
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          ]
        }
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      "providerMetadata": {
        "dateUpdated": "2026-03-23T10:53:35.655Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "vdb-entry",
            "x_refsource_REDHAT"
          ],
          "url": "https://access.redhat.com/security/cve/CVE-2026-4633"
        },
        {
          "name": "RHBZ#2450247",
          "tags": [
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            "x_refsource_REDHAT"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450247"
        }
      ],
      "timeline": [
        {
          "lang": "en",
          "time": "2026-03-23T08:34:37.879Z",
          "value": "Reported to Red Hat."
        },
        {
          "lang": "en",
          "time": "2025-03-23T05:05:00.000Z",
          "value": "Made public."
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      ],
      "title": "Keycloak: keycloak: user enumeration via differential error messages",
      "workarounds": [
        {
          "lang": "en",
          "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      },
      "x_redhatCweChain": "CWE-209: Generation of Error Message Containing Sensitive Information"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2026-4633",
    "datePublished": "2026-03-23T10:53:35.655Z",
    "dateReserved": "2026-03-23T08:36:31.514Z",
    "dateUpdated": "2026-03-23T15:52:36.681Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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

GHSA-RHGQ-F8X5-J2JC

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

Tags

Sightings

Nomenclature