{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "c88d4c7b049e87998ac0a9f455aa545cc895ef92"
            },
            {
              "fixed": "6b396cc2f0365e684fc1d3547d18ef79fcee225d"
            },
            {
              "fixed": "87d0cecc900e55d55fc4dbfb43ac93e269c7a5b3"
            },
            {
              "fixed": "b1226e37eb3754d389721c135db6107db94c7a72"
            },
            {
              "fixed": "3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e"
            },
            {
              "fixed": "853ce31ca72097d23991a06876a2ccb5cb64b603"
            },
            {
              "fixed": "d42b2b6bb77ca40ee34ab74ad79305840b5f315d"
            },
            {
              "fixed": "7b6495ead2c611647f6b11441a852324e3eb8616"
            },
            {
              "fixed": "306039414932c80f8420695a24d4fe10c84ccfb2"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.36"
            },
            {
              "fixed": "5.10.253"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.203"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.169"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.130"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.77"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.18"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23405.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\napparmor: fix: limit the number of levels of policy namespaces\n\nCurrently the number of policy namespaces is not bounded relying on\nthe user namespace limit. However policy namespaces aren't strictly\ntied to user namespaces and it is possible to create them and nest\nthem arbitrarily deep which can be used to exhaust system resource.\n\nHard cap policy namespaces to the same depth as user namespaces.",
  "id": "CVE-2026-23405",
  "modified": "2026-07-08T05:35:53.608385106Z",
  "published": "2026-04-01T08:36:35.697Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/306039414932c80f8420695a24d4fe10c84ccfb2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3f8699b3ee0c04b4b9bc27b82cd89a40e81e1d2e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6b396cc2f0365e684fc1d3547d18ef79fcee225d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7b6495ead2c611647f6b11441a852324e3eb8616"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/853ce31ca72097d23991a06876a2ccb5cb64b603"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/87d0cecc900e55d55fc4dbfb43ac93e269c7a5b3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b1226e37eb3754d389721c135db6107db94c7a72"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d42b2b6bb77ca40ee34ab74ad79305840b5f315d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23405.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23405"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "summary": "apparmor: fix: limit the number of levels of policy namespaces"
}