{
  "threat_severity" : "Moderate",
  "public_date" : "2026-05-13T19:28:34Z",
  "bugzilla" : {
    "description" : "grafana: Grafana Auth Proxy: Unauthorized access due to incorrect IPv6 allow-list default",
    "id" : "2477262",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2477262"
  },
  "cvss3" : {
    "cvss3_base_score" : "7.4",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N",
    "status" : "verified"
  },
  "cwe" : "CWE-183",
  "details" : [ "When using an IPv6 allow-list for the Auth Proxy feature, it defaults to /32 addresses. Addresses specifying a mask explicitly are not affected; to mitigate easily, add the desired mask (usually /128) to the addresses. Only auth proxy is affected; Okta, SAML, LDAP, etc are unaffected here.", "A flaw in Grafana's Auth Proxy IPv6 allow-list incorrectly defaults to a broad /32 subnet mask instead of a strict /128. This misconfiguration allows remote attackers to bypass access restrictions, potentially leading to unauthorized access and data manipulation." ],
  "statement" : "A flaw in Grafana's Auth Proxy IPv6 allow-list defaults to an overly broad /32 mask, potentially allowing unauthorized access. This strictly affects Auth Proxy deployments using IPv6 allow-lists; other authentication methods are unaffected. This has been rated moderate since auth proxy authentication is not enabled by default on grafana shipped on RHEL.",
  "affected_release" : [ {
    "product_name" : "Multicluster Global Hub 1.5.6",
    "release_date" : "2026-07-21T00:00:00Z",
    "advisory" : "RHSA-2026:42852",
    "cpe" : "cpe:/a:redhat:multicluster_globalhub:1.5::el9",
    "package" : "multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1784562060"
  } ],
  "package_state" : [ {
    "product_name" : "Red Hat Advanced Cluster Management for Kubernetes 2",
    "fix_state" : "Affected",
    "package_name" : "rhacm2/acm-grafana-rhel9",
    "cpe" : "cpe:/a:redhat:acm:2"
  }, {
    "product_name" : "Red Hat Ceph Storage 5",
    "fix_state" : "Fix deferred",
    "package_name" : "rhceph/rhceph-5-dashboard-rhel8",
    "cpe" : "cpe:/a:redhat:ceph_storage:5"
  }, {
    "product_name" : "Red Hat Ceph Storage 6",
    "fix_state" : "Fix deferred",
    "package_name" : "rhceph/rhceph-6-dashboard-rhel9",
    "cpe" : "cpe:/a:redhat:ceph_storage:6"
  }, {
    "product_name" : "Red Hat Ceph Storage 7",
    "fix_state" : "Fix deferred",
    "package_name" : "rhceph/grafana-rhel9",
    "cpe" : "cpe:/a:redhat:ceph_storage:7"
  }, {
    "product_name" : "Red Hat Ceph Storage 8",
    "fix_state" : "Fix deferred",
    "package_name" : "rhceph/grafana-rhel9",
    "cpe" : "cpe:/a:redhat:ceph_storage:8"
  }, {
    "product_name" : "Red Hat Ceph Storage 9",
    "fix_state" : "Fix deferred",
    "package_name" : "rhceph/grafana-rhel10",
    "cpe" : "cpe:/a:redhat:ceph_storage:9"
  }, {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Affected",
    "package_name" : "grafana",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Affected",
    "package_name" : "grafana",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Affected",
    "package_name" : "grafana",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-33376\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-33376\nhttps://grafana.com/security/security-advisories/cve-2026-33376" ],
  "name" : "CVE-2026-33376",
  "mitigation" : {
    "value" : "To mitigate this issue, explicitly specify the intended IPv6 address mask—typically /128 for a single host—within the Grafana Auth Proxy allow-list configuration. This overrides the incorrect default /32 mask, ensuring that network access restrictions are applied strictly as intended.\nFor RHEL: Update the whitelist directive under the [auth.proxy] section in /etc/grafana/grafana.ini. For example, if ::1 is the desired address, configure it explicitly as ::1/128. A restart of the Grafana service (systemctl restart grafana-server) is required for the changes to take effect.",
    "lang" : "en:us"
  },
  "csaw" : false
}