Vulnerability-Lookup

GHSA-78XG-W78V-WC27

Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33

Details

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: hci_core: Fix UAF in hci_unregister_dev()

hci_unregister_dev() does not disable cmd_timer and ncmd_timer before the hci_dev structure is freed. If a timeout fires during device teardown, the callback dereferences freed memory (including the hdev->reset function pointer), leading to a use-after-free.

Add disable_delayed_work_sync() calls alongside the existing disable_work_sync() calls to ensure both timers are fully quiesced before teardown proceeds.

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-74302"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-15T06:22:29Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_core: Fix UAF in hci_unregister_dev()\n\nhci_unregister_dev() does not disable cmd_timer and ncmd_timer\nbefore the hci_dev structure is freed. If a timeout fires\nduring device teardown, the callback dereferences freed memory\n(including the hdev-\u003ereset function pointer), leading to a\nuse-after-free.\n\nAdd disable_delayed_work_sync() calls alongside the existing\ndisable_work_sync() calls to ensure both timers are fully\nquiesced before teardown proceeds.",
  "id": "GHSA-78xg-w78v-wc27",
  "modified": "2026-08-17T06:33:37Z",
  "published": "2026-08-15T06:32:29Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74302"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/48c7ad6afcc58c2cda11fed39791708103b6a644"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5edcc018fa6e80b2c478454a4a8229c23d67c181"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/672d52d9412252e61b8de8d773ccdf5a277cf540"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a0fd1086a57b982f8c24ae4ab165c2af39fe1735"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-74302 (GCVE-0-2026-74302)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:58 – Updated: 2026-08-17 05:45

Title

Bluetooth: hci_core: Fix UAF in hci_unregister_dev()

Summary

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_core: Fix UAF in hci_unregister_dev() hci_unregister_dev() does not disable cmd_timer and ncmd_timer before the hci_dev structure is freed. If a timeout fires during device teardown, the callback dereferences freed memory (including the hdev->reset function pointer), leading to a use-after-free. Add disable_delayed_work_sync() calls alongside the existing disable_work_sync() calls to ensure both timers are fully quiesced before teardown proceeds.

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/48c7ad6afcc58c2cd…
https://git.kernel.org/stable/c/a0fd1086a57b982f8…
https://git.kernel.org/stable/c/672d52d9412252e61…
https://git.kernel.org/stable/c/5edcc018fa6e80b2c…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 0d151a103775dd9645c78c97f77d6e2a5298d913 , < 48c7ad6afcc58c2cda11fed39791708103b6a644 (git) Affected: 0d151a103775dd9645c78c97f77d6e2a5298d913 , < a0fd1086a57b982f8c24ae4ab165c2af39fe1735 (git) Affected: 0d151a103775dd9645c78c97f77d6e2a5298d913 , < 672d52d9412252e61b8de8d773ccdf5a277cf540 (git) Affected: 0d151a103775dd9645c78c97f77d6e2a5298d913 , < 5edcc018fa6e80b2c478454a4a8229c23d67c181 (git) Affected: 48542881997e17b49dc16b93fe910e0cfcf7a9f9 (git) Affected: 9cfc84b1d464cc024286f42a090718f9067b80ed (git) Affected: ddeda6ca5f218b668b560d90fc31ae469adbfd92 (git) Affected: d2ce562a5aff1dcd0c50d9808ea825ef90da909f (git) Affected: 96600c2e5ee8213dbab5df1617293d8e847bb4fa (git) Affected: d6cbce18370641a21dd889e8613d8153df15eb39 (git) Affected: 3f939bd73fed12dddc2a32a76116c19ca47c7678 (git) Affected: 4.19.319 , < 4.20 (semver) Affected: 5.4.281 , < 5.5 (semver) Affected: 5.10.223 , < 5.11 (semver) Affected: 5.15.164 , < 5.16 (semver) Affected: 6.1.101 , < 6.2 (semver) Affected: 6.6.42 , < 6.7 (semver) Affected: 6.9.11 , < 6.10 (semver)
Linux	Linux	Affected: 6.10 Unaffected: 0 , < 6.10 (semver) Unaffected: 6.12.97 , ≤ 6.12.* (semver) Unaffected: 6.18.40 , ≤ 6.18.* (semver) Unaffected: 7.1.5 , ≤ 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_core.c"
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          "vendor": "Linux",
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              "status": "affected",
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            },
            {
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              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "48542881997e17b49dc16b93fe910e0cfcf7a9f9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "9cfc84b1d464cc024286f42a090718f9067b80ed",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ddeda6ca5f218b668b560d90fc31ae469adbfd92",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "d2ce562a5aff1dcd0c50d9808ea825ef90da909f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "96600c2e5ee8213dbab5df1617293d8e847bb4fa",
              "versionType": "git"
            },
            {
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              "version": "d6cbce18370641a21dd889e8613d8153df15eb39",
              "versionType": "git"
            },
            {
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              "version": "3f939bd73fed12dddc2a32a76116c19ca47c7678",
              "versionType": "git"
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              "status": "affected",
              "version": "4.19.319",
              "versionType": "semver"
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              "status": "affected",
              "version": "5.4.281",
              "versionType": "semver"
            },
            {
              "lessThan": "5.11",
              "status": "affected",
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              "versionType": "semver"
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            {
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              "status": "affected",
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              "versionType": "semver"
            },
            {
              "lessThan": "6.2",
              "status": "affected",
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              "versionType": "semver"
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            {
              "lessThan": "6.7",
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              "version": "6.6.42",
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              "status": "affected",
              "version": "6.9.11",
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          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "6.10"
            },
            {
              "lessThan": "6.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
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            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
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              "versionType": "semver"
            },
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              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
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        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
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                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "vulnerable": true
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                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.10",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.19.319",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.4.281",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.10.223",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "5.15.164",
                  "vulnerable": true
                },
                {
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                  "versionStartIncluding": "6.1.101",
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                {
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                  "vulnerable": true
                }
              ],
              "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_core: Fix UAF in hci_unregister_dev()\n\nhci_unregister_dev() does not disable cmd_timer and ncmd_timer\nbefore the hci_dev structure is freed. If a timeout fires\nduring device teardown, the callback dereferences freed memory\n(including the hdev-\u003ereset function pointer), leading to a\nuse-after-free.\n\nAdd disable_delayed_work_sync() calls alongside the existing\ndisable_work_sync() calls to ensure both timers are fully\nquiesced before teardown proceeds."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The UAF is reached only during hci_unregister_dev() teardown (e.g. closing /dev/vhci, USB/btusb disconnect, hci_ldisc detach, or driver removal); adjacent Bluetooth peers can arm cmd_timer/ncmd_timer via HCI timeouts but cannot invoke unregister, so exploitation requires local device/syscall access.\nAC:L - An attacker controls both sides of the race\u2014arming cmd_timer (2s) or ncmd_timer (4s) by withholding HCI command completions while closing /dev/vhci to run hci_unregister_dev(), and disable_work_sync(cmd_work) can queue cmd_timer immediately before teardown; the cycle is repeatable.\nPR:L - vhci_open() has no capable() check, so any principal granted /dev/vhci (syzkaller, containers, Android bluetooth uid, permissive udev) can create/destroy virtual HCI controllers and inject frames without init-namespace root, matching prior hci_unregister_dev teardown UAF scores.\nUI:N - The attacker performs device creation, HCI traffic injection, and teardown from its own process via open/write/close on /dev/vhci or equivalent local transport; no victim interaction or cooperation is required beyond existing device-node access.\nS:U - Corruption is confined to kernel slab memory and workqueue/timer state within the same kernel security authority; exploitation yields standard kernel privilege escalation, not VM escape, IOMMU bypass, or cross-sandbox boundary crossing.\nC:H - hci_cmd_timeout() and hci_ncmd_timeout() dereference the freed hci_dev (req_skb, flags, workqueue, name) after kfree(); UAF on the hci_dev slab enables controlled reallocation and arbitrary kernel memory read/pointer disclosure via heap spraying.\nI:H - hci_cmd_timeout() invokes the freed hdev-\u003ereset function pointer and re-queues cmd_work on hdev-\u003eworkqueue; attacker-controlled contents in the reclaimed hci_dev object provide arbitrary write and control-flow hijack primitives per kernel UAF scoring guidance.\nA:H - Timer callbacks operating on freed hci_dev memory cause KASAN slab-use-after-free reports, kernel oops/panic, and can queue work onto destroyed workqueues; even failed exploitation reliably crashes or hangs the affected controller path."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:45:38.299Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/48c7ad6afcc58c2cda11fed39791708103b6a644"
        },
        {
          "url": "https://git.kernel.org/stable/c/a0fd1086a57b982f8c24ae4ab165c2af39fe1735"
        },
        {
          "url": "https://git.kernel.org/stable/c/672d52d9412252e61b8de8d773ccdf5a277cf540"
        },
        {
          "url": "https://git.kernel.org/stable/c/5edcc018fa6e80b2c478454a4a8229c23d67c181"
        }
      ],
      "title": "Bluetooth: hci_core: Fix UAF in hci_unregister_dev()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74302",
    "datePublished": "2026-08-15T05:58:04.638Z",
    "dateReserved": "2026-08-15T05:44:03.882Z",
    "dateUpdated": "2026-08-17T05:45:38.299Z",
    "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.

Action not permitted

GHSA-78XG-W78V-WC27

CVE-2026-74302 (GCVE-0-2026-74302)

Tags

Sightings

Nomenclature