CVE-2026-74530 (GCVE-0-2026-74530)
Vulnerability from cvelistv5
Published
2026-08-15 12:27
Modified
2026-10-21 12:45
Severity ?
8.8 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback There is theoretical UAF if the conn is freed while the hci_sync task is running. Hold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to match the previous behavior.
References
Impacted products
Vendor Product Version
Linux Linux Version: 620810ac1f7f1133a9ac403e132b3ad6995ddf39
Version: 024421cf39923927ab2b5fe895d1d922b9abe67f
Version: 024421cf39923927ab2b5fe895d1d922b9abe67f
Version: 024421cf39923927ab2b5fe895d1d922b9abe67f
Version: ee0586ad64a805eaf1a9a10100e908627a561e34
Version: 6.12.28   ≤
Version: 6.14.6   ≤
Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-74530",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-16T18:59:16.031043Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-16T19:05:53.346Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "117d8bcaf1abc348185e8ab6a4ba9f8f516849a0",
              "status": "affected",
              "version": "620810ac1f7f1133a9ac403e132b3ad6995ddf39",
              "versionType": "git"
            },
            {
              "lessThan": "ff5625d27415ace5667bf87ebc16c3a0a98db22f",
              "status": "affected",
              "version": "024421cf39923927ab2b5fe895d1d922b9abe67f",
              "versionType": "git"
            },
            {
              "lessThan": "2d91e6244b69d752503b2d44020d8b0e323dbd38",
              "status": "affected",
              "version": "024421cf39923927ab2b5fe895d1d922b9abe67f",
              "versionType": "git"
            },
            {
              "lessThan": "56e78b670356caab0b607e8aad4cf819a1909d07",
              "status": "affected",
              "version": "024421cf39923927ab2b5fe895d1d922b9abe67f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ee0586ad64a805eaf1a9a10100e908627a561e34",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.114",
              "status": "affected",
              "version": "6.12.28",
              "versionType": "semver"
            },
            {
              "lessThan": "6.15",
              "status": "affected",
              "version": "6.14.6",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/hci_sync.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.114",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.114",
                  "versionStartIncluding": "6.12.28",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.57",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.14.6",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: hold conn in hci_connect_big_sync() callback\n\nThere is theoretical UAF if the conn is freed while the hci_sync task is\nrunning.\n\nHold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to\nmatch the previous behavior."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - The bug is in Bluetooth LE ISO BIG Create Sync handling (hci_connect_big_sync), reachable via adjacent BLE traffic that drives HCI events (e.g. HCI_EVT_LE_BIG_INFO_ADV_REPORT through iso_connect_ind) and via local ISO sockets; Bluetooth kernel bugs are scored as Adjacent, not Network.\nAC:L - After 024421cf3992 the path blocks in __hci_cmd_sync_status_sk for up to conn_timeout while only holding a bare hci_conn pointer; an attacker who can open/close an ISO broadcast socket (or race teardown during that wait) controls both sides of the race and can reliably trigger the UAF.\nPR:N - Exploitation does not require root or CAP_NET_ADMIN; adjacent attackers can trigger the vulnerable code through unauthenticated over-the-air BLE broadcasts processed by the kernel HCI layer, and local exploitation only needs standard Bluetooth/ISO socket access available to unprivileged users/apps with Bluetooth permission.\nUI:N - No victim interaction is required beyond attacker-controlled actions such as creating an ISO broadcast listener socket, starting BIG sync, and concurrently closing the socket to free hci_conn while hci_sync work is still running; exploitation does not depend on another user opening files or mounting resources.\nS:U - The use-after-free corrupts kernel heap memory within the Bluetooth/hci_conn subsystem and can lead to local privilege escalation, but it does not cross a VM, IOMMU, or sandbox security boundary into another authority domain.\nC:H - This is a kernel heap use-after-free of struct hci_conn; freed connection objects can be reallocated and read through subsequent dereferences in create_big_complete and hci_le_big_create_sync, providing a standard path to arbitrary kernel memory disclosure.\nI:H - UAF on struct hci_conn allows corrupting connection flags and adjacent heap contents; the structure contains function pointers (cleanup, connect_cfm_cb, disconn_cfm_cb) and is large enough to support heap grooming toward arbitrary write or control-flow hijack.\nA:H - Use-after-free during clear_bit on conn-\u003eflags in create_big_complete, or accessing conn fields after teardown during the blocking BIG sync command, can cause kernel oops/panic and repeated disruption; UAF availability impact is rated High per kernel guidance."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T12:45:48.364Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/117d8bcaf1abc348185e8ab6a4ba9f8f516849a0"
        },
        {
          "url": "https://git.kernel.org/stable/c/ff5625d27415ace5667bf87ebc16c3a0a98db22f"
        },
        {
          "url": "https://git.kernel.org/stable/c/2d91e6244b69d752503b2d44020d8b0e323dbd38"
        },
        {
          "url": "https://git.kernel.org/stable/c/56e78b670356caab0b607e8aad4cf819a1909d07"
        }
      ],
      "title": "Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74530",
    "datePublished": "2026-08-15T12:27:45.381Z",
    "dateReserved": "2026-08-15T05:44:03.912Z",
    "dateUpdated": "2026-10-21T12:45:48.364Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-74530\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"total\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-10-16T18:59:16.031043Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-10-16T18:59:16.644Z\"}}], \"cna\": {\"title\": \"Bluetooth: hci_sync: hold conn in hci_connect_big_sync() callback\", \"metrics\": [{\"cvssV3_1\": {\"version\": \"3.1\", \"baseScore\": 8.8, \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"AV:A - The bug is in Bluetooth LE ISO BIG Create Sync handling (hci_connect_big_sync), reachable via adjacent BLE traffic that drives HCI events (e.g. HCI_EVT_LE_BIG_INFO_ADV_REPORT through iso_connect_ind) and via local ISO sockets; Bluetooth kernel bugs are scored as Adjacent, not Network.\\nAC:L - After 024421cf3992 the path blocks in __hci_cmd_sync_status_sk for up to conn_timeout while only holding a bare hci_conn pointer; an attacker who can open/close an ISO broadcast socket (or race teardown during that wait) controls both sides of the race and can reliably trigger the UAF.\\nPR:N - Exploitation does not require root or CAP_NET_ADMIN; adjacent attackers can trigger the vulnerable code through unauthenticated over-the-air BLE broadcasts processed by the kernel HCI layer, and local exploitation only needs standard Bluetooth/ISO socket access available to unprivileged users/apps with Bluetooth permission.\\nUI:N - No victim interaction is required beyond attacker-controlled actions such as creating an ISO broadcast listener socket, starting BIG sync, and concurrently closing the socket to free hci_conn while hci_sync work is still running; exploitation does not depend on another user opening files or mounting resources.\\nS:U - The use-after-free corrupts kernel heap memory within the Bluetooth/hci_conn subsystem and can lead to local privilege escalation, but it does not cross a VM, IOMMU, or sandbox security boundary into another authority domain.\\nC:H - This is a kernel heap use-after-free of struct hci_conn; freed connection objects can be reallocated and read through subsequent dereferences in create_big_complete and hci_le_big_create_sync, providing a standard path to arbitrary kernel memory disclosure.\\nI:H - UAF on struct hci_conn allows corrupting connection flags and adjacent heap contents; the structure contains function pointers (cleanup, connect_cfm_cb, disconn_cfm_cb) and is large enough to support heap grooming toward arbitrary write or control-flow hijack.\\nA:H - Use-after-free during clear_bit on conn-\u003eflags in create_big_complete, or accessing conn fields after teardown during the blocking BIG sync command, can cause kernel oops/panic and repeated disruption; UAF availability impact is rated High per kernel guidance.\"}]}], \"affected\": [{\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"620810ac1f7f1133a9ac403e132b3ad6995ddf39\", \"lessThan\": \"117d8bcaf1abc348185e8ab6a4ba9f8f516849a0\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"024421cf39923927ab2b5fe895d1d922b9abe67f\", \"lessThan\": \"ff5625d27415ace5667bf87ebc16c3a0a98db22f\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"024421cf39923927ab2b5fe895d1d922b9abe67f\", \"lessThan\": \"2d91e6244b69d752503b2d44020d8b0e323dbd38\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"024421cf39923927ab2b5fe895d1d922b9abe67f\", \"lessThan\": \"56e78b670356caab0b607e8aad4cf819a1909d07\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"ee0586ad64a805eaf1a9a10100e908627a561e34\", \"versionType\": \"git\"}, {\"status\": \"affected\", \"version\": \"6.12.28\", \"lessThan\": \"6.12.114\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"6.14.6\", \"lessThan\": \"6.15\", \"versionType\": \"semver\"}], \"programFiles\": [\"net/bluetooth/hci_sync.c\"], \"defaultStatus\": \"unaffected\"}, {\"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\", \"vendor\": \"Linux\", \"product\": \"Linux\", \"versions\": [{\"status\": \"affected\", \"version\": \"6.15\"}, {\"status\": \"unaffected\", \"version\": \"0\", \"lessThan\": \"6.15\", \"versionType\": \"semver\"}, {\"status\": \"unaffected\", \"version\": \"6.12.114\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.12.*\"}, {\"status\": \"unaffected\", \"version\": \"6.18.57\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"6.18.*\"}, {\"status\": \"unaffected\", \"version\": \"7.1.8\", \"versionType\": \"semver\", \"lessThanOrEqual\": \"7.1.*\"}, {\"status\": \"unaffected\", \"version\": \"7.2\", \"versionType\": \"original_commit_for_fix\", \"lessThanOrEqual\": \"*\"}], \"programFiles\": [\"net/bluetooth/hci_sync.c\"], \"defaultStatus\": \"affected\"}], \"references\": [{\"url\": \"https://git.kernel.org/stable/c/117d8bcaf1abc348185e8ab6a4ba9f8f516849a0\"}, {\"url\": \"https://git.kernel.org/stable/c/ff5625d27415ace5667bf87ebc16c3a0a98db22f\"}, {\"url\": \"https://git.kernel.org/stable/c/2d91e6244b69d752503b2d44020d8b0e323dbd38\"}, {\"url\": \"https://git.kernel.org/stable/c/56e78b670356caab0b607e8aad4cf819a1909d07\"}], \"x_generator\": {\"engine\": \"bippy-1.2.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"In the Linux kernel, the following vulnerability has been resolved:\\n\\nBluetooth: hci_sync: hold conn in hci_connect_big_sync() callback\\n\\nThere is theoretical UAF if the conn is freed while the hci_sync task is\\nrunning.\\n\\nHold refcount to avoid that. Handle NULL hcon, return 0 + do nothing to\\nmatch the previous behavior.\"}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.12.114\", \"versionStartIncluding\": \"6.12.28\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"6.18.57\", \"versionStartIncluding\": \"6.15\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"7.1.8\", \"versionStartIncluding\": \"6.15\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"7.2\", \"versionStartIncluding\": \"6.15\"}, {\"criteria\": \"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionStartIncluding\": \"6.14.6\"}], \"operator\": \"OR\"}]}], \"providerMetadata\": {\"orgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"shortName\": \"Linux\", \"dateUpdated\": \"2026-10-21T12:45:48.364Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-74530\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-10-21T12:45:48.364Z\", \"dateReserved\": \"2026-08-15T05:44:03.912Z\", \"assignerOrgId\": \"416baaa9-dc9f-4396-8d5f-8c081fb06d67\", \"datePublished\": \"2026-08-15T12:27:45.381Z\", \"assignerShortName\": \"Linux\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.