{
  "threat_severity" : "Low",
  "public_date" : "2026-01-15T00:00:00Z",
  "bugzilla" : {
    "description" : "org.keycloak/keycloak-quarkus-server: Keycloak: Proxy bypass due to improper handling of matrix parameters in URL paths",
    "id" : "2429869",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2429869"
  },
  "cvss3" : {
    "cvss3_base_score" : "3.7",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N",
    "status" : "draft"
  },
  "cwe" : "CWE-20",
  "details" : [ "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.", "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." ],
  "statement" : "This vulnerability is rated Low for Red Hat Keycloak. The flaw arises from Keycloak's acceptance of RFC-compliant matrix parameters in URL paths, which can be mishandled by certain reverse proxy configurations. This may allow an unauthenticated attacker to bypass proxy-level path filtering and potentially expose administrative or sensitive endpoints that are intended to be unreachable externally. Exploitation depends on the specific reverse proxy configuration.",
  "acknowledgement" : "Red Hat would like to thank Alexander Schwartz (RedHat) for reporting this issue.",
  "package_state" : [ {
    "product_name" : "Red Hat Build of Keycloak",
    "fix_state" : "Affected",
    "package_name" : "org.keycloak/keycloak-quarkus-server",
    "cpe" : "cpe:/a:redhat:build_keycloak:"
  }, {
    "product_name" : "Red Hat JBoss Enterprise Application Platform 8",
    "fix_state" : "Fix deferred",
    "package_name" : "keycloak-quarkus-server",
    "cpe" : "cpe:/a:redhat:jboss_enterprise_application_platform:8"
  }, {
    "product_name" : "Red Hat JBoss Enterprise Application Platform 8",
    "fix_state" : "Fix deferred",
    "package_name" : "keycloak-quarkus-server-app",
    "cpe" : "cpe:/a:redhat:jboss_enterprise_application_platform:8"
  }, {
    "product_name" : "Red Hat JBoss Enterprise Application Platform 8",
    "fix_state" : "Fix deferred",
    "package_name" : "keycloak-quarkus-server-deployment",
    "cpe" : "cpe:/a:redhat:jboss_enterprise_application_platform:8"
  }, {
    "product_name" : "Red Hat JBoss Enterprise Application Platform Expansion Pack",
    "fix_state" : "Fix deferred",
    "package_name" : "keycloak-quarkus-server",
    "cpe" : "cpe:/a:redhat:jbosseapxp"
  }, {
    "product_name" : "Red Hat JBoss Enterprise Application Platform Expansion Pack",
    "fix_state" : "Fix deferred",
    "package_name" : "keycloak-quarkus-server-app",
    "cpe" : "cpe:/a:redhat:jbosseapxp"
  }, {
    "product_name" : "Red Hat JBoss Enterprise Application Platform Expansion Pack",
    "fix_state" : "Fix deferred",
    "package_name" : "keycloak-quarkus-server-deployment",
    "cpe" : "cpe:/a:redhat:jbosseapxp"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-0976\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-0976" ],
  "name" : "CVE-2026-0976",
  "mitigation" : {
    "value" : "To mitigate this issue, ensure that all administrative and sensitive endpoints within Keycloak are adequately protected by robust authentication and authorization policies, independent of any reverse proxy path filtering. Operators should review Keycloak's internal access controls to confirm that access to these endpoints is restricted to authorized users and roles.",
    "lang" : "en:us"
  },
  "csaw" : false
}