FKIE_CVE-2026-0976

Vulnerability from fkie_nvd - Published: 2026-01-15 13:16 - Updated: 2026-06-17 10:11
Severity
3.7 (Low) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
Summary
A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable.
References
secalert@redhat.comhttps://access.redhat.com/security/cve/CVE-2026-0976
secalert@redhat.comhttps://bugzilla.redhat.com/show_bug.cgi?id=2429869
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://access.redhat.com/downloads/content/package-browser/",
          "cpes": [
            "cpe:/a:redhat:build_keycloak:"
          ],
          "defaultStatus": "affected",
          "packageName": "org.keycloak/keycloak-quarkus-server",
          "product": "Red Hat Build of Keycloak",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
          "cpes": [
            "cpe:/a:redhat:jboss_enterprise_application_platform:8"
          ],
          "defaultStatus": "affected",
          "packageName": "keycloak-quarkus-server",
          "product": "Red Hat JBoss Enterprise Application Platform 8",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
          "cpes": [
            "cpe:/a:redhat:jboss_enterprise_application_platform:8"
          ],
          "defaultStatus": "affected",
          "packageName": "keycloak-quarkus-server-app",
          "product": "Red Hat JBoss Enterprise Application Platform 8",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
          "cpes": [
            "cpe:/a:redhat:jboss_enterprise_application_platform:8"
          ],
          "defaultStatus": "affected",
          "packageName": "keycloak-quarkus-server-deployment",
          "product": "Red Hat JBoss Enterprise Application Platform 8",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
          "cpes": [
            "cpe:/a:redhat:jbosseapxp"
          ],
          "defaultStatus": "affected",
          "packageName": "keycloak-quarkus-server",
          "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
          "cpes": [
            "cpe:/a:redhat:jbosseapxp"
          ],
          "defaultStatus": "affected",
          "packageName": "keycloak-quarkus-server-app",
          "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack",
          "vendor": "Red Hat"
        },
        {
          "collectionURL": "https://access.redhat.com/jbossnetwork/restricted/listSoftware.html",
          "cpes": [
            "cpe:/a:redhat:jbosseapxp"
          ],
          "defaultStatus": "affected",
          "packageName": "keycloak-quarkus-server-deployment",
          "product": "Red Hat JBoss Enterprise Application Platform Expansion Pack",
          "vendor": "Red Hat"
        }
      ],
      "source": "secalert@redhat.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in Keycloak. This improper input validation vulnerability occurs because Keycloak accepts RFC-compliant matrix parameters in URL path segments, while common reverse proxy configurations may ignore or mishandle them. A remote attacker can craft requests to mask path segments, potentially bypassing proxy-level path filtering. This could expose administrative or sensitive endpoints that operators believe are not externally reachable."
    },
    {
      "lang": "es",
      "value": "Se encontr\u00f3 un defecto en Keycloak. Esta vulnerabilidad de validaci\u00f3n de entrada incorrecta ocurre porque Keycloak acepta par\u00e1metros de matriz conformes con RFC en segmentos de ruta de URL, mientras que las configuraciones comunes de proxy inverso pueden ignorarlos o manejarlos incorrectamente. Un atacante remoto puede elaborar solicitudes para enmascarar segmentos de ruta, eludiendo potencialmente el filtrado de rutas a nivel de proxy. Esto podr\u00eda exponer puntos finales administrativos o sensibles que los operadores creen que no son accesibles externamente."
    }
  ],
  "id": "CVE-2026-0976",
  "lastModified": "2026-06-17T10:11:43.213",
  "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": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-0976",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-01-15T14:44:09.361820Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-01-15T13:16:04.910",
  "references": [
    {
      "source": "secalert@redhat.com",
      "url": "https://access.redhat.com/security/cve/CVE-2026-0976"
    },
    {
      "source": "secalert@redhat.com",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2429869"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ],
      "source": "secalert@redhat.com",
      "type": "Secondary"
    }
  ]
}


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