CVE-2026-68393 (GCVE-0-2026-68393)

Vulnerability from cvelistv5 – Published: 2026-08-10 12:04 – Updated: 2026-08-17 05:04
VLAI
Title
Bluetooth: hci_sync: extend conn_hash lookup critical sections
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: extend conn_hash lookup critical sections Using RCU-protected pointers outside the critical sections without refcount is incorrect and may result to UAF. Extend critical section to cover both hci_conn_hash lookup and use of the returned conn. Add surrounding rcu_read_lock() also when return value is not used, in preparation for RCU lockdep requirement to hci_lookup_le_connect(). This avoids concurrent deletion of the conn before we are done dereferencing it. Also, make sure to hold hdev->lock when accessing hdev->accept_list.
Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 6d0417e4e1cf66fd917f06f0454958362714ef7d , < 83b7e67698d0b93f685875ce82c8d335436834f7 (git)
Affected: 6d0417e4e1cf66fd917f06f0454958362714ef7d , < 38326774df6198df0cc2744cc73bf77cb741c538 (git)
Affected: 6d0417e4e1cf66fd917f06f0454958362714ef7d , < d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d (git)
Affected: eb8b860e87b296bd1874c79a668081efd00f9754 (git)
Affected: 94bf6380e936339a700c0b3171a49baf512aa70b (git)
Affected: 6.12.28 , < 6.13 (semver)
Affected: 6.14.6 , < 6.15 (semver)
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Linux Linux Affected: 6.15
Unaffected: 0 , < 6.15 (semver)
Unaffected: 6.18.42 , ≤ 6.18.* (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "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": [
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              "status": "affected",
              "version": "6d0417e4e1cf66fd917f06f0454958362714ef7d",
              "versionType": "git"
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              "status": "affected",
              "version": "6d0417e4e1cf66fd917f06f0454958362714ef7d",
              "versionType": "git"
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              "status": "affected",
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              "versionType": "git"
            },
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              "version": "eb8b860e87b296bd1874c79a668081efd00f9754",
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            {
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              "version": "94bf6380e936339a700c0b3171a49baf512aa70b",
              "versionType": "git"
            },
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          "vendor": "Linux",
          "versions": [
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              "versionType": "semver"
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              "versionType": "original_commit_for_fix"
            }
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        }
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      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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                  "vulnerable": true
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              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: extend conn_hash lookup critical sections\n\nUsing RCU-protected pointers outside the critical sections without\nrefcount is incorrect and may result to UAF.\n\nExtend critical section to cover both hci_conn_hash lookup and use of\nthe returned conn.\n\nAdd surrounding rcu_read_lock() also when return value is not used, in\npreparation for RCU lockdep requirement to hci_lookup_le_connect().\n\nThis avoids concurrent deletion of the conn before we are done\ndereferencing it.\n\nAlso, make sure to hold hdev-\u003elock when accessing hdev-\u003eaccept_list."
        }
      ],
      "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 affected code is the Bluetooth HCI sync/scan management layer; both sides of the race are driven by LE radio events (connection complete, disconnect, periodic advertising sync creation/termination) from a device in radio range, requiring no local access.\nAC:L - A nearby attacker drives both sides of the race \u2014 repeated LE connect/disconnect and PA sync setup/teardown queue the hci_sync work while concurrently triggering hci_conn_del() on the event workqueue \u2014 so the window can be re-attempted arbitrarily until won.\nPR:N - The vulnerable hci_update_passive_scan_sync()/hci_update_accept_list_sync()/hci_le_set_ext_scan_param_sync() paths are invoked automatically by the kernel in response to incoming LE connection and periodic-advertising events; the remote attacker needs no credentials or pairing on the target.\nUI:N - No victim action is needed \u2014 background LE scanning and accept-list updates are performed autonomously by the host stack whenever connection state changes.\nS:U - The use-after-free occurs in kernel memory and its impact is confined to the kernel\u0027s own security authority, with no crossing into a separate authorization scope such as a hypervisor or IOMMU boundary.\nC:H - The freed hci_conn is read after release (conn-\u003edst, conn-\u003edst_type, PHY parameters), and a heap-groomed replacement object lets the attacker read attacker-chosen or sensitive kernel data, which can additionally be exfiltrated via the resulting accept-list/scan parameters.\nI:H - hci_conn is kfree()\u0027d via bt_link_release() while still referenced, so reallocating the slab with a controlled object yields write/control-flow primitives typical of slab use-after-free, enabling kernel memory corruption and privilege escalation.\nA:H - Dereferencing the freed hci_conn readily causes slab corruption, KASAN splats, or an oops/panic in the Bluetooth workqueues, taking down the kernel."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:04:41.234Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/83b7e67698d0b93f685875ce82c8d335436834f7"
        },
        {
          "url": "https://git.kernel.org/stable/c/38326774df6198df0cc2744cc73bf77cb741c538"
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        {
          "url": "https://git.kernel.org/stable/c/d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d"
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      ],
      "title": "Bluetooth: hci_sync: extend conn_hash lookup critical sections",
      "x_generator": {
        "engine": "bippy-1.2.0"
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  "cveMetadata": {
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-68393",
    "datePublished": "2026-08-10T12:04:12.564Z",
    "dateReserved": "2026-07-30T09:28:09.388Z",
    "dateUpdated": "2026-08-17T05:04:41.234Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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      "cve": "CVE-2026-68393",
      "date": "2026-08-20",
      "epss": "0.00242",
      "percentile": "0.15638"
    },
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    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-13T23:27:36+00:00",
      "cve": "CVE-2026-68393",
      "id": "CVE-2026-68393",
      "initial_release_date": "2026-08-10T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "92",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Bluetooth: hci_sync: extend conn_hash lookup critical sections",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68393.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-08-13T16:22:34Z",
      "cve": "CVE-2026-68393",
      "id": "CVE-2026-68393",
      "initial_release_date": "2026-08-13T16:22:34Z",
      "product_status:known_affected": "17",
      "product_status:known_not_affected": "279",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-68393",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-68393.json",
      "version": "2"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.