{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "5222470b2fbb3740f931f189db33dd1367b1ae75"
            },
            {
              "fixed": "1797ee11451f1b2be69863a9f5bd43b948813fdf"
            },
            {
              "fixed": "d2324a9317f00013facb0ba00b00440e19d2af5e"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.18.0"
            },
            {
              "fixed": "6.19.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43391.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnsfs: tighten permission checks for handle opening\n\nEven privileged services should not necessarily be able to see other\nprivileged service's namespaces so they can't leak information to each\nother. Use may_see_all_namespaces() helper that centralizes this policy\nuntil the nstree adapts.",
  "id": "CVE-2026-43391",
  "modified": "2026-07-08T05:37:57.135064997Z",
  "published": "2026-05-08T14:21:36.012Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1797ee11451f1b2be69863a9f5bd43b948813fdf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d2324a9317f00013facb0ba00b00440e19d2af5e"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43391.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43391"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "nsfs: tighten permission checks for handle opening"
}