{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ffdc52fbbd5835a936ad683c943d6d103a2d4514"
            },
            {
              "fixed": "5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5"
            },
            {
              "fixed": "08d575ee89393fd812dbdca7b5d7b4574cd5a564"
            },
            {
              "fixed": "476ef286a7a5db8bda51325dc0c45887b4d99d9a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.17.0"
            },
            {
              "fixed": "6.18.57"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98995.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: reset the old parent's -\u003eovermount in mnt_change_mountpoint()\n\n__umount_mnt() resets -\u003eovermount of the parent when it unmounts the\nmount that overmounts it. mnt_change_mountpoint() doesn't. It moves the\nmount to its new parent and leaves the old one pointing at it.\n\nFor a mount that is moved beneath in attach_recursive_mnt() that doesn't\nmatter. The new mount has already reset -\u003eovermount of the old parent by\nthe time the old top mount is moved onto it.\n\nIt matters for reparent() though. propagate_umount() moves a surviving\novermount onto the first ancestor that isn't going to be unmounted. The\nmount it was taken from is unmounted immediately afterwards. If a file\ndescriptor keeps that unmounted mount alive -\u003eovermount points at the\nmoved mount. That's a dangling pointer and UAF as the moved mount is\nunmounted and freed.\n\ndo_lock_mount() follows -\u003eovermount from the target path under\nmount_lock. With a file descriptor on such a mount as the target of a\nmount beneath topmost_overmount() walks into the freed mount and\ndo_lock_mount() takes references on whatever it finds there.\n\nSo reset -\u003eovermount of the old parent in mnt_change_mountpoint() the\nsame way __umount_mnt() does. A mount's -\u003eovermount is then always a\nmount that is attached to it.",
  "id": "CVE-2026-98995",
  "modified": "2026-10-28T02:30:40.151123651Z",
  "published": "2026-10-23T12:20:14.155Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/08d575ee89393fd812dbdca7b5d7b4574cd5a564"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/476ef286a7a5db8bda51325dc0c45887b4d99d9a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e0a1f2c753a79749bc2ead3ae2f2ede3941daa5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98995.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98995"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.2",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "namespace: reset the old parent's -\u003eovermount in mnt_change_mountpoint()"
}