Vulnerability-Lookup

GHSA-MRP3-X3FF-8XJ3

Vulnerability from github – Published: 2026-08-10 15:33 – Updated: 2026-08-14 00:31

Details

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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-68393"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T13:20:32Z",
    "severity": "HIGH"
  },
  "details": "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.",
  "id": "GHSA-mrp3-x3ff-8xj3",
  "modified": "2026-08-14T00:31:57Z",
  "published": "2026-08-10T15:33:49Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-68393"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/38326774df6198df0cc2744cc73bf77cb741c538"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/83b7e67698d0b93f685875ce82c8d335436834f7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

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

Vulnerability from cvelistv5 – Published: 2026-08-10 12:04 – Updated: 2026-08-17 05:04

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

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/83b7e67698d0b93f6…
https://git.kernel.org/stable/c/38326774df6198df0…
https://git.kernel.org/stable/c/d5efd6e4b8b0634af…

Impacted products

2 products

Vendor	Product	Version
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)
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": [
            {
              "lessThan": "83b7e67698d0b93f685875ce82c8d335436834f7",
              "status": "affected",
              "version": "6d0417e4e1cf66fd917f06f0454958362714ef7d",
              "versionType": "git"
            },
            {
              "lessThan": "38326774df6198df0cc2744cc73bf77cb741c538",
              "status": "affected",
              "version": "6d0417e4e1cf66fd917f06f0454958362714ef7d",
              "versionType": "git"
            },
            {
              "lessThan": "d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d",
              "status": "affected",
              "version": "6d0417e4e1cf66fd917f06f0454958362714ef7d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "eb8b860e87b296bd1874c79a668081efd00f9754",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "94bf6380e936339a700c0b3171a49baf512aa70b",
              "versionType": "git"
            },
            {
              "lessThan": "6.13",
              "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": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "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": "6.18.42",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "6.15",
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                },
                {
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                {
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                {
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                  "versionStartIncluding": "6.14.6",
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                }
              ],
              "negate": false,
              "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"
        },
        {
          "url": "https://git.kernel.org/stable/c/d5efd6e4b8b0634af6843178fe1a7dd2b2178a3d"
        }
      ],
      "title": "Bluetooth: hci_sync: extend conn_hash lookup critical sections",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
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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"
}

Sightings

Author	Source	Type	Date	Other

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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

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GHSA-MRP3-X3FF-8XJ3

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

Tags

Sightings

Nomenclature