{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "cdae7c07e3e3509eaabc18c1640a55dc5b99c179"
            },
            {
              "fixed": "2b5f47a710172c962ef42d1b732b04d2ad0dce21"
            },
            {
              "fixed": "95839a67ea56ca35732aad7f711404a3127cfe2d"
            },
            {
              "fixed": "0a84ab9271936c11e84e511bb52fc5682f8b6726"
            },
            {
              "fixed": "b4621e5ef63405c317a84b711faf3bd75b3c6a94"
            },
            {
              "fixed": "f31c6d220f455b5af63590302b30e1b932d14599"
            },
            {
              "fixed": "830c8a9b467e7d3a158483d37fa7dc13892b293a"
            },
            {
              "fixed": "ed9455ef4bd9babc90f92e526abe3fb68c1a8709"
            },
            {
              "fixed": "928abe19fbf0127003abcb1ea69cabc1c897d0ab"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.15.0"
            },
            {
              "fixed": "5.10.259"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.210"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.176"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.143"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.93"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.35"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.0.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63891.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nthunderbolt: property: Cap recursion depth in __tb_property_parse_dir()\n\nA DIRECTORY entry's value field is used as the dir_offset for a\nrecursive call into __tb_property_parse_dir() with no depth counter.\nA crafted peer that chains DIRECTORY entries into a back-reference\nloop drives the parser until the kernel stack is exhausted and the\nguard page fires.  Any untrusted XDomain peer (cable, dock, in-line\ninspector, adjacent host) that reaches the PROPERTIES_REQUEST\ncontrol-plane exchange can trigger this without authentication.\n\nThread a depth counter through tb_property_parse() and\n__tb_property_parse_dir(), and reject blocks that exceed\nTB_PROPERTY_MAX_DEPTH = 8.  That is comfortably larger than any\nobserved legitimate XDomain layout.\n\nOperators who do not need XDomain host-to-host discovery can disable\nthe path entirely with thunderbolt.xdomain=0 on the kernel command\nline.",
  "id": "CVE-2026-63891",
  "modified": "2026-07-21T03:41:49.801851950Z",
  "published": "2026-07-19T14:55:02.840Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0a84ab9271936c11e84e511bb52fc5682f8b6726"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b5f47a710172c962ef42d1b732b04d2ad0dce21"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/830c8a9b467e7d3a158483d37fa7dc13892b293a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/928abe19fbf0127003abcb1ea69cabc1c897d0ab"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/95839a67ea56ca35732aad7f711404a3127cfe2d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b4621e5ef63405c317a84b711faf3bd75b3c6a94"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ed9455ef4bd9babc90f92e526abe3fb68c1a8709"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f31c6d220f455b5af63590302b30e1b932d14599"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63891.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63891"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "thunderbolt: property: Cap recursion depth in __tb_property_parse_dir()"
}