nstree: tighten permission checks for listing

{
  "id": "662db4a237daeea1738278b0f1da3417447b0345fd80ec1dda064c60761ae768",
  "url": "https://osv.dev/vulnerability/CVE-2026-43390",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "nstree: tighten permission checks for listing",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: nstree: tighten permission checks for listing Even privileged services should not necessarily be able to see other privileged service's namespaces so they can't leak information to each other. Use may_see_all_namespaces() helper that centralizes this policy until the nstree adapts.",
    "evidence": "osv:CVE-2026-43390",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.19.9",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-43390",
      "aliases": [
        "CVE-2026-43390"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "76b6f5dfb3fda76fce1f9990d6fa58adc711122b"
                },
                {
                  "fixed": "0abd81645fc95ec6a9d4e4813000f22c5efc0ff4"
                },
                {
                  "fixed": "8d76afe84fa2babf604b3c173730d4d2b067e361"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43390.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "6.19.9"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-43390.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.933165096Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/0abd81645fc95ec6a9d4e4813000f22c5efc0ff4",
        "https://git.kernel.org/stable/c/8d76afe84fa2babf604b3c173730d4d2b067e361",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43390.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-43390",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43390.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-43390",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 496489,
  "published_at": "2026-05-08T14:21:35.337+00:00"
}