{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "bc2bf338d54b7aadaed49bb45b9e10d4592b2a46"
            },
            {
              "fixed": "0f19d54e2524f0bf183b82f365ae4e49b4a2f788"
            },
            {
              "fixed": "2dd0298905e97795a9c5ec30cf5b41975f821632"
            },
            {
              "fixed": "1cd4e9b7967dab48c9f79a00b06ffff7208c0993"
            },
            {
              "fixed": "5ccc99d58f94fad258c9c375715b3974e48620e8"
            },
            {
              "fixed": "bbf5f639918dc011aaf60aab8480218758ee68c5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.8.0"
            },
            {
              "fixed": "6.6.148"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.101"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.42"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68186.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbinfmt_misc: set have_execfd only once the interpreter is opened\n\nload_misc_binary() raises bprm-\u003ehave_execfd as soon as it sees the 'O'\n(or 'C') flag. This happens well before it opens the interpreter. If\nthat open fails the flag stays set on the bprm. binfmt_misc is at the\nhead of the format list so an interpreter open failure that returns\n-ENOEXEC lets the search fall through to a later format. This means it\nruns the matched binary directly having never staged an interpreter. So\nbprm-\u003eexecutable is NULL while have_execfd falsely claims a descriptor\nis present.\n\nConsequently, begin_new_exec() dereferences the missing executable:\n\n  would_dump(bprm, bprm-\u003eexecutable);\n\nand NULL derefs. Had it not, the hand-off later in the same function\nwould have failed anyway. FD_ADD(0, bprm-\u003eexecutable) rejects a NULL\nfile with -ENOMEM. Both sites are past the point of no return so the\nexec cannot be unwound either way.\n\nThis can be reached by unprivileged users as binfmt_misc can be mounted\nin user namespaces. So a user can register an 'O' entry whose\ninterpreter lives on a FUSE mount, have the FUSE server fail the open\nwith -ENOEXEC and execute a native ELF file that matches the entry.\n\nhave_execfd only means anything alongside the executable it describes\nwhich is not set until the interpreter has been opened and staged.\nSo lets raise it there, next to execfd_creds, which is already set at\nthat point. An open failure now leaves it clear, so the fallback format\nderives credentials from the binary and emits no AT_EXECFD, as it would\nfor any native exec. The argv rewrite load_misc_binary() performs before\nthe open is still not undone. This means the binary sees the interpreter\npath in argv[0] and its own path in argv[1] but that predates this\nchange and only became observable once the exec stopped faulting.",
  "id": "CVE-2026-68186",
  "modified": "2026-08-18T03:31:09.808127812Z",
  "published": "2026-08-10T11:59:58.299Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0f19d54e2524f0bf183b82f365ae4e49b4a2f788"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1cd4e9b7967dab48c9f79a00b06ffff7208c0993"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2dd0298905e97795a9c5ec30cf5b41975f821632"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5ccc99d58f94fad258c9c375715b3974e48620e8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bbf5f639918dc011aaf60aab8480218758ee68c5"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68186.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68186"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "binfmt_misc: set have_execfd only once the interpreter is opened"
}