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CVE-2026-4633

Full vulnerability record from the local CVENow database.

Description

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
LOW
CVSS score
3.7 (v3.1)
Vulnerability status
Modified
Source identifier
Published
2026-03-23 11:16:25.053000
Last modified
2026-10-22 22:18:07.123000
View original CVE JSON
{
  "id": "CVE-2026-4633",
  "sourceIdentifier": "[email protected]",
  "published": "2026-03-23T11:16:25.053",
  "lastModified": "2026-10-22T22:18:07.123",
  "vulnStatus": "Modified",
  "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."
    },
    {
      "lang": "es",
      "value": "Se encontró una falla en Keycloak. Un atacante remoto puede explotar mensajes de error diferenciales durante el flujo de inicio de sesión 'identity-first' cuando las Organizaciones están habilitadas. Esta vulnerabilidad permite a un atacante determinar la existencia de usuarios, lo que lleva a la revelación de información a través de la enumeración de usuarios."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "Red Hat",
          "product": "Red Hat build of Keycloak 26.4.12",
          "defaultStatus": "unaffected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.4::el9"
          ]
        },
        {
          "vendor": "Red Hat",
          "product": "Red Hat Build of Keycloak",
          "defaultStatus": "affected",
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "packageName": "rhbk/keycloak-rhel9",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:"
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4
      },
      {
        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
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          "baseScore": 3.7,
          "baseSeverity": "LOW",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 1.4
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-03-23T15:07:15.419255Z",
          "id": "CVE-2026-4633",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-209"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
            {
              "vulnerable": true,
              "criteria": "cpe:2.3:a:redhat:build_of_keycloak:-:*:*:*:-:*:*:*",
              "matchCriteriaId": "E5C930CB-4EAD-497B-A44B-D880F2A1F85B"
            }
          ]
        }
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  ],
  "references": [
    {
      "url": "https://access.redhat.com/errata/RHSA-2026:19596",
      "source": "[email protected]"
    },
    {
      "url": "https://access.redhat.com/security/cve/CVE-2026-4633",
      "source": "[email protected]",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2450247",
      "source": "[email protected]",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Vendor Advisory"
      ]
    }
  ]
}