CVE-2026-80721 (GCVE-0-2026-80721)

Vulnerability from cvelistv5 – Published: 2026-08-28 06:53 – Updated: 2026-08-30 07:08
VLAI
Title
Bluetooth: ISO: ensure no dangling hcon references in iso_conn
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: ensure no dangling hcon references in iso_conn After iso_conn_del(), ISO sockets should not dereference the hcon any more. Currently, clearing iso_conn::hcon relies on iso_conn_del() releasing the last reference to the iso_conn. Simplify this by explicitly clearing conn->hcon in iso_conn_del(), to avoid more complex reasoning on races about who holds the last reference.
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: dc26097bdb864a0d5955b9a25e43376ffc1af99b , < e941799c31f68e67ce0976efb38a79101f921b64 (git)
Affected: dc26097bdb864a0d5955b9a25e43376ffc1af99b , < cdce8af9291d8a1f8916c271de029bf558d9e8ec (git)
Affected: dc26097bdb864a0d5955b9a25e43376ffc1af99b , < aa9f7cb2bd3a2be998ceb739fc9a2f986eba43eb (git)
Affected: f53e7489273dc2bb307bf50f319b3762d45534f0 (git)
Affected: a58d0f5dac322e16cc75334d000666512341bde5 (git)
Affected: 6.11.11 , < 6.12 (semver)
Affected: 6.12.2 , < 6.13 (semver)
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Linux Linux Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 6.18.44 , ≤ 6.18.* (semver)
Unaffected: 7.1.8 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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{
  "containers": {
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      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/iso.c"
          ],
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              "versionType": "git"
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              "version": "6.11.11",
              "versionType": "semver"
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          "product": "Linux",
          "programFiles": [
            "net/bluetooth/iso.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
              "version": "6.13"
            },
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
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              "versionType": "semver"
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              "version": "7.1.8",
              "versionType": "semver"
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
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                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.44",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: ensure no dangling hcon references in iso_conn\n\nAfter iso_conn_del(), ISO sockets should not dereference the hcon any\nmore.  Currently, clearing iso_conn::hcon relies on iso_conn_del()\nreleasing the last reference to the iso_conn.\n\nSimplify this by explicitly clearing conn-\u003ehcon in iso_conn_del(), to\navoid more complex reasoning on races about who holds the last\nreference."
        }
      ],
      "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 ISO connection teardown (iso_conn_del/iso_conn_free); reachable when an adjacent peer triggers HCI disconnect/connect-failure events or sends ISO traffic processed by iso_recv, without network or physical USB access.\nAC:L - An adjacent attacker controls both sides of the refcount race by timing remote disconnects and ISO packets against local teardown; no rare layout or victim-specific state beyond an active ISO session is required.\nPR:N - No local privileges are required on the victim; an unauthenticated adjacent Bluetooth peer can trigger iso_disconn_cfm/iso_connect_cfm teardown on phones and desktops with Bluetooth and LE Audio/ISO enabled.\nUI:N - Exploitation needs no victim interaction during the attack; once Bluetooth is on and an ISO link exists (e.g., LE Audio), remote disconnect and ISO traffic alone can hit the race.\nS:U - The flaw causes kernel heap use-after-free on hci_conn via dangling iso_conn::hcon references; impact stays within kernel memory safety, not a VM escape or cross-authority boundary.\nC:H - After hci_conn_del frees hcon, iso_conn still holds conn-\u003ehcon; subsequent iso_conn_free or socket paths dereference freed hci_conn memory, a classic UAF read primitive.\nI:H - Use-after-free on hci_conn enables corrupting connection management fields and hci_conn_drop state; such kernel heap UAF bugs are routinely leveraged for arbitrary write and code execution.\nA:H - Dereferencing freed hci_conn in iso_conn_free or ISO socket teardown reliably causes kernel oops or panic, giving unprivileged adjacent attackers a repeatable denial-of-service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-30T07:08:36.447Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/e941799c31f68e67ce0976efb38a79101f921b64"
        },
        {
          "url": "https://git.kernel.org/stable/c/cdce8af9291d8a1f8916c271de029bf558d9e8ec"
        },
        {
          "url": "https://git.kernel.org/stable/c/aa9f7cb2bd3a2be998ceb739fc9a2f986eba43eb"
        }
      ],
      "title": "Bluetooth: ISO: ensure no dangling hcon references in iso_conn",
      "x_generator": {
        "engine": "bippy-1.2.0"
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    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80721",
    "datePublished": "2026-08-28T06:53:17.278Z",
    "dateReserved": "2026-08-26T14:34:25.788Z",
    "dateUpdated": "2026-08-30T07:08:36.447Z",
    "state": "PUBLISHED"
  },
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      "date": "2026-09-23",
      "epss": "0.00225",
      "percentile": "0.13496"
    },
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      "cve": "CVE-2026-80721",
      "id": "msrc_CVE-2026-80721",
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      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "Bluetooth: ISO: ensure no dangling hcon references in iso_conn",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-80721.json",
      "version": "1"
    },
    "nvd": {
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                "product": "Linux",
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                ],
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            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: ensure no dangling hcon references in iso_conn\n\nAfter iso_conn_del(), ISO sockets should not dereference the hcon any\nmore.  Currently, clearing iso_conn::hcon relies on iso_conn_del()\nreleasing the last reference to the iso_conn.\n\nSimplify this by explicitly clearing conn-\u003ehcon in iso_conn_del(), to\navoid more complex reasoning on races about who holds the last\nreference."
          }
        ],
        "id": "CVE-2026-80721",
        "lastModified": "2026-08-30T07:17:21.673",
        "metrics": {
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                "attackVector": "ADJACENT_NETWORK",
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                "baseScore": 8.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
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        "vulnStatus": "Received"
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      "current_release_date": "2026-09-01T12:37:09+00:00",
      "cve": "CVE-2026-80721",
      "id": "CVE-2026-80721",
      "initial_release_date": "2026-08-28T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Bluetooth: ISO: ensure no dangling hcon references in iso_conn",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80721.json",
      "version": "3"
    },
    "suse_vex": {
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      "current_release_date": "2026-09-22T16:31:00Z",
      "cve": "CVE-2026-80721",
      "id": "CVE-2026-80721",
      "initial_release_date": "2026-08-28T16:33:05Z",
      "product_status:first_fixed": "60",
      "product_status:known_affected": "67",
      "product_status:known_not_affected": "286",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-80721",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-80721.json",
      "version": "7"
    }
  }
}



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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.



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