CVE-2026-74535 (GCVE-0-2026-74535)

Vulnerability from cvelistv5 – Published: 2026-08-15 12:27 – Updated: 2026-08-17 05:48
VLAI
Title
Bluetooth: ISO: avoid deadlocks in iso_sock_timeout
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: avoid deadlocks in iso_sock_timeout iso_sock_timeout() takes lock_sock, so sync disabling the timer while holding that lock may deadlock. iso_sock_timeout() may also run concurrently with iso_conn_del(), which leads to UAF [Task 1] [Task hdev->workqueue] iso_sock_timeout iso_conn_del iso_conn_hold_unless_zero iso_chan_del `------------> iso_conn_put caller frees hcon iso_conn_put iso_conn_free conn->hcon->iso_data = NULL; /* UAF */ Fix the deadlock by removing the disable from the lock_sock sections. Move the timer from iso_conn to iso_pinfo to decouple it from iso_conn which may need to be freed in lock_sock section. Convert some of the clear_timer to disable_timer.
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: a58d0f5dac322e16cc75334d000666512341bde5 , < 16d89a63e08280abeef7218970a3bbd7ca62b021 (git)
Affected: dc26097bdb864a0d5955b9a25e43376ffc1af99b , < 82e982f54f962f72646868ddbb2c3bd9ea178568 (git)
Affected: dc26097bdb864a0d5955b9a25e43376ffc1af99b , < 3c3d5f85db80145636bb991a6005e2760012b985 (git)
Affected: dc26097bdb864a0d5955b9a25e43376ffc1af99b , < 200fa1629c57a3ca2b03d3ca63fd3a9bfd910c43 (git)
Affected: f53e7489273dc2bb307bf50f319b3762d45534f0 (git)
Affected: 6.12.2 , < 6.12.103 (semver)
Affected: 6.11.11 , < 6.12 (semver)
guessed Create a notification for this product.
Linux Linux Affected: 6.13
Unaffected: 0 , < 6.13 (semver)
Unaffected: 6.12.103 , ≤ 6.12.* (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.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/iso.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "16d89a63e08280abeef7218970a3bbd7ca62b021",
              "status": "affected",
              "version": "a58d0f5dac322e16cc75334d000666512341bde5",
              "versionType": "git"
            },
            {
              "lessThan": "82e982f54f962f72646868ddbb2c3bd9ea178568",
              "status": "affected",
              "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
              "versionType": "git"
            },
            {
              "lessThan": "3c3d5f85db80145636bb991a6005e2760012b985",
              "status": "affected",
              "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
              "versionType": "git"
            },
            {
              "lessThan": "200fa1629c57a3ca2b03d3ca63fd3a9bfd910c43",
              "status": "affected",
              "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f53e7489273dc2bb307bf50f319b3762d45534f0",
              "versionType": "git"
            },
            {
              "lessThan": "6.12.103",
              "status": "affected",
              "version": "6.12.2",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12",
              "status": "affected",
              "version": "6.11.11",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/iso.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "lessThan": "6.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.103",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.44",
              "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": "6.12.103",
                  "versionStartIncluding": "6.12.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.44",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.8",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "6.13",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "6.11.11",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: avoid deadlocks in iso_sock_timeout\n\niso_sock_timeout() takes lock_sock, so sync disabling the timer while\nholding that lock may deadlock.\n\niso_sock_timeout() may also run concurrently with iso_conn_del(), which\nleads to UAF\n\n        [Task 1]                      [Task hdev-\u003eworkqueue]\n        iso_sock_timeout              iso_conn_del\n          iso_conn_hold_unless_zero     iso_chan_del\n                           `------------\u003e iso_conn_put\n                                      caller frees hcon\n          iso_conn_put\n            iso_conn_free\n              conn-\u003ehcon-\u003eiso_data = NULL; /* UAF */\n\nFix the deadlock by removing the disable from the lock_sock sections.\nMove the timer from iso_conn to iso_pinfo to decouple it from iso_conn\nwhich may need to be freed in lock_sock section. Convert some of the\nclear_timer to disable_timer."
        }
      ],
      "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 the Bluetooth ISO socket layer (BTPROTO_ISO); iso_sock_timeout and iso_conn_del are reached via HCI disconnect/connect events from an adjacent BLE peer and local ISO socket syscalls, which per kernel guidance is Adjacent not Network.\nAC:L - Exploitation is a race between iso_sock_timeout and iso_conn_del that an attacker can reliably force by controlling ISO connect/disconnect timing and socket send timeouts (SO_SNDTIMEO) on concurrent workqueues, so success does not depend on uncontrollable conditions.\nPR:N - An adjacent Bluetooth attacker can trigger iso_conn_del through remote HCI disconnect/failure events without any credentials or privileges on the victim host; only a normal active or pending ISO/LE Audio session must exist on the target.\nUI:N - No deliberate victim interaction beyond routine Bluetooth/LE Audio operation is required; exploitation can occur in the background while an ISO connection is pending or active, without opening files or performing a separate enabling action.\nS:U - The UAF/deadlock corrupts kernel heap memory on the host and enables local privilege escalation within the kernel security boundary, not a cross-boundary escape such as VM guest-to-host or IOMMU bypass.\nC:H - iso_conn_free dereferences conn-\u003ehcon after concurrent iso_conn_del frees the hci_conn (UAF on conn-\u003ehcon-\u003eiso_data), enabling arbitrary kernel memory read/disclosure through heap corruption per UAF guidance.\nI:H - The UAF permits writes through conn-\u003ehcon-\u003eiso_data and hci_conn_drop on freed hci_conn memory, providing heap corruption primitives that can be leveraged for arbitrary kernel writes or code execution.\nA:H - The UAF causes kernel oops/panic on freed hci_conn access, and the lock_sock versus disable_delayed_work_sync deadlock in iso_sock_timeout/iso_conn_del paths can hang the system; both crash and deadlock map to High availability impact."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:48:24.441Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/16d89a63e08280abeef7218970a3bbd7ca62b021"
        },
        {
          "url": "https://git.kernel.org/stable/c/82e982f54f962f72646868ddbb2c3bd9ea178568"
        },
        {
          "url": "https://git.kernel.org/stable/c/3c3d5f85db80145636bb991a6005e2760012b985"
        },
        {
          "url": "https://git.kernel.org/stable/c/200fa1629c57a3ca2b03d3ca63fd3a9bfd910c43"
        }
      ],
      "title": "Bluetooth: ISO: avoid deadlocks in iso_sock_timeout",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-74535",
    "datePublished": "2026-08-15T12:27:48.449Z",
    "dateReserved": "2026-08-15T05:44:03.913Z",
    "dateUpdated": "2026-08-17T05:48:24.441Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-74535",
      "date": "2026-09-20",
      "epss": "0.00241",
      "percentile": "0.15622"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "net/bluetooth/iso.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "16d89a63e08280abeef7218970a3bbd7ca62b021",
                    "status": "affected",
                    "version": "a58d0f5dac322e16cc75334d000666512341bde5",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "82e982f54f962f72646868ddbb2c3bd9ea178568",
                    "status": "affected",
                    "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "3c3d5f85db80145636bb991a6005e2760012b985",
                    "status": "affected",
                    "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "200fa1629c57a3ca2b03d3ca63fd3a9bfd910c43",
                    "status": "affected",
                    "version": "dc26097bdb864a0d5955b9a25e43376ffc1af99b",
                    "versionType": "git"
                  },
                  {
                    "status": "affected",
                    "version": "f53e7489273dc2bb307bf50f319b3762d45534f0",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "6.12.103",
                    "status": "affected",
                    "version": "6.12.2",
                    "versionType": "semver"
                  },
                  {
                    "lessThan": "6.12",
                    "status": "affected",
                    "version": "6.11.11",
                    "versionType": "semver"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "net/bluetooth/iso.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "6.13"
                  },
                  {
                    "lessThan": "6.13",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.12.*",
                    "status": "unaffected",
                    "version": "6.12.103",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.44",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.1.*",
                    "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: ISO: avoid deadlocks in iso_sock_timeout\n\niso_sock_timeout() takes lock_sock, so sync disabling the timer while\nholding that lock may deadlock.\n\niso_sock_timeout() may also run concurrently with iso_conn_del(), which\nleads to UAF\n\n        [Task 1]                      [Task hdev-\u003eworkqueue]\n        iso_sock_timeout              iso_conn_del\n          iso_conn_hold_unless_zero     iso_chan_del\n                           `------------\u003e iso_conn_put\n                                      caller frees hcon\n          iso_conn_put\n            iso_conn_free\n              conn-\u003ehcon-\u003eiso_data = NULL; /* UAF */\n\nFix the deadlock by removing the disable from the lock_sock sections.\nMove the timer from iso_conn to iso_pinfo to decouple it from iso_conn\nwhich may need to be freed in lock_sock section. Convert some of the\nclear_timer to disable_timer."
          }
        ],
        "id": "CVE-2026-74535",
        "lastModified": "2026-08-17T06:19:50.587",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "ADJACENT_NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 8.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-08-15T13:17:58.837",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/16d89a63e08280abeef7218970a3bbd7ca62b021"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/200fa1629c57a3ca2b03d3ca63fd3a9bfd910c43"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/3c3d5f85db80145636bb991a6005e2760012b985"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/82e982f54f962f72646868ddbb2c3bd9ea178568"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-19T18:10:24+00:00",
      "cve": "CVE-2026-74535",
      "id": "CVE-2026-74535",
      "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: ISO: avoid deadlocks in iso_sock_timeout",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-74535.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-15T01:19:22Z",
      "cve": "CVE-2026-74535",
      "id": "CVE-2026-74535",
      "initial_release_date": "2026-08-15T23:50:49Z",
      "product_status:known_affected": "76",
      "product_status:known_not_affected": "286",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-74535",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-74535.json",
      "version": "6"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.