CVE-2026-74529 (GCVE-0-2026-74529)

Vulnerability from cvelistv5 – Published: 2026-08-15 12:27 – Updated: 2026-08-17 05:48
VLAI
Title
Bluetooth: hci_sync: hold conn in hci_connect_pa_sync() callback
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: hold conn in hci_connect_pa_sync() callback There is theoretical UAF if the conn is freed while the hci_sync task is running. Hold refcount to avoid that.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 6d0417e4e1cf66fd917f06f0454958362714ef7d , < c53c70ec289ee12f20c4f1b2fbfd151762c01f67 (git)
Affected: 6d0417e4e1cf66fd917f06f0454958362714ef7d , < 44fc74069d8988f2825246f9401218e29de2c0ab (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: 7.1.8 , ≤ 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": "c53c70ec289ee12f20c4f1b2fbfd151762c01f67",
              "status": "affected",
              "version": "6d0417e4e1cf66fd917f06f0454958362714ef7d",
              "versionType": "git"
            },
            {
              "lessThan": "44fc74069d8988f2825246f9401218e29de2c0ab",
              "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": "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": "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": "6.12.28",
                  "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_pa_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."
        }
      ],
      "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 - Reached only via local AF_BLUETOOTH BTPROTO_ISO SOCK_SEQPACKET listen() for LE broadcast PA sync (iso_listen_bis\u2192hci_pa_create_sync\u2192hci_connect_pa_sync); no over-the-air packet parsing triggers the bug and a remote Bluetooth peer alone cannot invoke it.\nAC:L - Use-after-free race is attacker-controlled: a local process can listen() to start hci_le_pa_create_sync and immediately close/unlink the socket to drop the PA_LINK hci_conn while cmd_sync_work is still running, retrying until the callback dereferences freed memory.\nPR:L - ISO sockets perform no capability checks in iso_sock_create/bt_sock_create (only init_net), so any unprivileged local user who can open AF_BLUETOOTH sockets on a BT_ISO-capable host can reach hci_connect_pa_sync without CAP_NET_ADMIN or root.\nUI:N - Exploitation requires no victim action; the attacker opens, binds, and listens on their own ISO socket and races teardown\u2014typical on phones/headsets running LE Audio broadcast receivers with Bluetooth access granted to the attacking app/process.\nS:U - Impact stays within kernel memory via hci_conn UAF in create_pa_complete/hci_le_pa_create_sync; this is standard kernel memory corruption/privilege escalation, not a cross-boundary escape (VM, IOMMU, or sandbox).\nC:H - UAF of struct hci_conn lets an attacker influence freed slab contents and read adjacent kernel data through hci_conn_valid(), conn-\u003eflags, and conn-\u003eiso_qos dereferences during async PA sync work and error callbacks.\nI:H - Freed hci_conn is written via set_bit/clear_bit on conn-\u003eflags and error-path hci_connect_cfm()/hci_conn_add_unset in create_pa_complete; heap grooming of the reclaimed allocation enables arbitrary kernel writes and control-flow hijack.\nA:H - Dereferencing or deleting a freed hci_conn in hci_cmd_sync_work reliably causes kernel memory corruption, oops, or panic; UAFs in this subsystem have been observed to crash the host even when not fully exploited for privilege escalation."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:48:18.894Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c53c70ec289ee12f20c4f1b2fbfd151762c01f67"
        },
        {
          "url": "https://git.kernel.org/stable/c/44fc74069d8988f2825246f9401218e29de2c0ab"
        }
      ],
      "title": "Bluetooth: hci_sync: hold conn in hci_connect_pa_sync() callback",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74529",
    "datePublished": "2026-08-15T12:27:44.783Z",
    "dateReserved": "2026-08-15T05:44:03.912Z",
    "dateUpdated": "2026-08-17T05:48:18.894Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74529",
      "date": "2026-09-21",
      "epss": "0.0012",
      "percentile": "0.02138"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "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": "c53c70ec289ee12f20c4f1b2fbfd151762c01f67",
                    "status": "affected",
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                    "versionType": "git"
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                  },
                  {
                    "status": "affected",
                    "version": "eb8b860e87b296bd1874c79a668081efd00f9754",
                    "versionType": "git"
                  },
                  {
                    "status": "affected",
                    "version": "94bf6380e936339a700c0b3171a49baf512aa70b",
                    "versionType": "git"
                  },
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                    "version": "6.12.28",
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                    "version": "6.14.6",
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                  }
                ]
              },
              {
                "defaultStatus": "affected",
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                "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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                    "version": "6.15"
                  },
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                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
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                    "status": "unaffected",
                    "version": "7.1.8",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.2",
                    "versionType": "original_commit_for_fix"
                  }
                ]
              }
            ],
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_sync: hold conn in hci_connect_pa_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."
          }
        ],
        "id": "CVE-2026-74529",
        "lastModified": "2026-08-17T06:19:49.770",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-08-15T13:17:58.190",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/44fc74069d8988f2825246f9401218e29de2c0ab"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/c53c70ec289ee12f20c4f1b2fbfd151762c01f67"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-17T14:55:56+00:00",
      "cve": "CVE-2026-74529",
      "id": "CVE-2026-74529",
      "initial_release_date": "2026-08-15T00:00:00+00:00",
      "product_status:known_affected": "184",
      "product_status:known_not_affected": "90",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Bluetooth: hci_sync: hold conn in hci_connect_pa_sync() callback",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74529.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-21T00:40:06Z",
      "cve": "CVE-2026-74529",
      "id": "CVE-2026-74529",
      "initial_release_date": "2026-08-15T23:50:57Z",
      "product_status:known_not_affected": "284",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-74529",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-74529.json",
      "version": "4"
    }
  }
}



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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

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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.