cve-2026-107889

MEDIUM CVSS 5.5 fkie_nvd
Description

A flaw was found in the login theme rendering component of Keycloak. The issue occurs because the security filter responsible for cleaning user input can be bypassed, allowing a realm administrator to store malicious scripts in display fields. This could result in unauthorized JavaScript execution in the browsers of users visiting the login page, potentially leading to data exposure or session interference.

Timeline
Published
unknown
Last Modified
unknown
CVSS Details
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
Affected Products

No product information available.

Weaknesses (CWE)
CWE-79
CVSS metrics
Version Base Severity Vector Exploitability Impact Source
3.1 5.5 MEDIUM CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N 2.3 2.7 secalert@redhat.com
NVD metadata
NVD status
Awaiting Analysis
Source identifier
secalert@redhat.com
References
Linked Vulnerabilities
06eeb817-d93d-11f1-908f-3c7c3fba4204 freebsd 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "defaultStatus": "unaffected",
          "packageName": "keycloak-services",
          "product": "Red Hat build of Keycloak 26.6.8",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:26.6::el9"
          ],
          "defaultStatus": "unaffected",
          "packageName": "rhbk/keycloak-rhel9",
          "product": "Red Hat build of Keycloak 26.6.8",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:red_hat_single_sign_on:7"
          ],
          "defaultStatus": "unaffected",
          "packageName": "keycloak-services",
          "product": "Red Hat Single Sign-On 7",
          "vendor": "Red Hat"
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in the login theme rendering component of Keycloak. The issue occurs because the security filter responsible for cleaning user input can be bypassed, allowing a realm administrator to store malicious scripts in display fields. This could result in unauthorized JavaScript execution in the browsers of users visiting the login page, potentially leading to data exposure or session interference."
    }
  ],
  "id": "CVE-2026-107889",
  "lastModified": "2026-11-06T11:17:03.693",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "HIGH",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.3,
        "impactScore": 2.7,
        "source": "secalert@redhat.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-107889",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-13T16:45:42.974434Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-09T05:16:44.583",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/errata/RHSA-2026:95761"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2026-107889"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2548355"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    }
  ]
}
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