{
  "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-2026-74483",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-74483",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-08-15T12:27:15.709Z",
    "updatedAt": "2026-08-23T12:47:24.496Z",
    "importedAt": "2026-10-24T01:58:30.346Z",
    "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": "binfmt_misc: don't leak the user namespace when the mount fails",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nbinfmt_misc: don't leak the user namespace when the mount fails\n\nbm_get_tree() takes a reference to the user namespace and hands it to\nget_tree_keyed() as the sget key. sget_fc() moves that reference into\nsb->s_fs_info and clears fc->s_fs_info, so from that point on the\nsuperblock owns it and bm_free() doesn't see it anymore.\n\nThe superblock drops it in ->put_super(). But generic_shutdown_super()\nonly calls ->put_super() from inside the if (sb->s_root) branch, so\nnothing releases it when bm_fill_super() fails:\n\n- The kzalloc_obj() failure leaves s_root NULL and the whole branch is\n  skipped.\n\n- A simple_fill_super() failure in the file loop leaves s_root set, but\n  s_op still points at simple_super_operations, which has no\n  ->put_super(). bm_fill_super() installs s_ops only once\n  simple_fill_super() returned success, and installing it earlier\n  wouldn't help either because simple_fill_super() overwrites s_op.\n\nEither way vfs_get_super() calls deactivate_locked_super() and the\nreference is gone for good. binfmt_misc mounts are available in a user\nnamespace and both the inode and the dentry cache are SLAB_ACCOUNT, so\nan unprivileged caller under a tight memory cgroup can fail\nsimple_fill_super() on demand and leak one user namespace per attempt.\n\nDrop the reference in ->kill_sb() instead, which runs unconditionally,\nthe same way nfsd and rpc_pipefs release their keyed s_fs_info.\n\nThat also stops ->put_super() from clearing s_fs_info while the\nsuperblock is still on @fs_supers. generic_shutdown_super() leaves it\nthere on purpose so that sget_fc() keeps finding it until kill_sb() has\nrun, but a NULL s_fs_info makes test_keyed_super() miss it, so a\nconcurrent mount for the same user namespace skips the grab_super()\nwait and creates a second superblock for a namespace that is still\nbeing torn down.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ffec017158d3aad8a6ffca1dfad63d63bde9caad"
            },
            {
              "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "867aed6a4848761190d5ebdedf9642648f97bceb"
            },
            {
              "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "87a4eb9bbb3497f749bbac612af22ddaa62d7b0d"
            },
            {
              "version": "21ca59b365c091d583f36ac753eaa8baf947be6f",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b8206f516fe7cbe785cf44bf09c17c438d7c3cad"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.7",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.7"
            },
            {
              "version": "6.12.105",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.46",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.1.8",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}