{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-98990",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-98990",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-10-23T12:20:09.349Z",
    "updatedAt": "2026-10-23T12:20:09.349Z",
    "importedAt": "2026-10-24T01:58:41.756Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "namespace: check a submount for references right before unmounting it",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nnamespace: check a submount for references right before unmounting it\n\nshrink_submounts() and mark_mounts_for_expiry() first collect all the\nmounts they are allowed to unmount and then unmount them.\n\nWhether a mount is busy is decided by propagate_mount_busy() on the\ntree. But unmounting the first mount changes the tree that the second\none propagates into. propagate_umount()\nmoves a surviving overmount off a copy it unmounts and mounts it where\nthe copy was mounted. If that's where the propagated copy of the second\nvictim is looked up the overmount becomes a candidate of the second\numount_tree(). It's childless and so trim_one() commits it without\nlooking at its reference count.\n\nSo a synchronous umount pulls out a busy mount that is in use somewhere\nelse and marks it MNT_SYNC_UMOUNT while it has users:\n\n  umount2(/tmp/plshrink/p1, 0) = 0 errno 0\n  cwd is (unreachable)\n\nThe same two umounts requested one after the other fail with EBUSY.\nThis needs a mount with MNT_SHRINKABLE, i.e., automounted submounts of\nNFS, AFS and CIFS or the tracefs mount below debugfs. Bind mounts\ninherit the flag.\n\nCheck each mount right before it is unmounted under the same hold of\nnamespace_sem and mount_lock as the umount itself. Make sure that the\nalgorithm stays linear.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "1064f874abc0d05eeed8993815f584d847b72486",
              "status": "affected",
              "versionType": "git",
              "lessThan": "f6394281834492c6516a405a348b545ae698a331"
            },
            {
              "version": "1064f874abc0d05eeed8993815f584d847b72486",
              "status": "affected",
              "versionType": "git",
              "lessThan": "6e4012e571867868b545c91ca9d6095fdb709907"
            },
            {
              "version": "1064f874abc0d05eeed8993815f584d847b72486",
              "status": "affected",
              "versionType": "git",
              "lessThan": "d73f04e92c1aab78d96ac6cadb234c8a3a373d22"
            },
            {
              "version": "1064f874abc0d05eeed8993815f584d847b72486",
              "status": "affected",
              "versionType": "git",
              "lessThan": "18902a23ef36f83d32bafc58ae2484e6bb4bb8ef"
            },
            {
              "version": "1064f874abc0d05eeed8993815f584d847b72486",
              "status": "affected",
              "versionType": "git",
              "lessThan": "32bf92416614a1e3ff3524fc6b780259c7aad3ef"
            },
            {
              "version": "5e6ef5ef6eaf690faad3a7c6c665ebf45d7b6ccf",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "839d42687dfce0ed0ea2c6bd8d707cc0e276fbe7",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "808e83e5add13152bd4a88346487de68395c136b",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "6de9d08a9718ee9c12ba6343c50141c2d633e3dc",
              "status": "affected",
              "versionType": "git"
            },
            {
              "version": "4.1.40",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.2"
            },
            {
              "version": "4.4.54",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.5"
            },
            {
              "version": "4.9.15",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.10"
            },
            {
              "version": "4.10.3",
              "status": "affected",
              "versionType": "semver",
              "lessThan": "4.11"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.11",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.11"
            },
            {
              "version": "6.6.160",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.113",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.57",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.2.11",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "version": "7.3",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}