{"id":"CVE-2026-74533","title":"Bluetooth: ISO: fix race of kfree vs kref_get_unless_zero","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: fix race of kfree vs kref_get_unless_zero\n\nhci_conn::iso_data is accessed and modified without lock or RCU.\nThis leads to a race\n\n    [Task hdev->workqu…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= dc26097bdb864a0d5955b9a25e43376ffc1af99b < 876a3e94c70d0859d1dad1c986112d4f0d99eba8","Linux >= dc26097bdb864a0d5955b9a25e43376ffc1af99b < af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c","Linux f53e7489273dc2bb307bf50f319b3762d45534f0","Linux a58d0f5dac322e16cc75334d000666512341bde5","Linux >= 6.11.11 < 6.12","Linux >= 6.12.2 < 6.13","Linux 6.13"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:59:22.174830Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:05:53.676Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74533","references":[{"url":"https://git.kernel.org/stable/c/876a3e94c70d0859d1dad1c986112d4f0d99eba8"},{"url":"https://git.kernel.org/stable/c/af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c"}],"tags":["cve.org"],"epss":0.0034,"epssPercentile":0.25943,"ingestedAt":"2026-10-16T19:46:24.347Z","slug":"CVE-2026-74533","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: ISO: fix race of kfree vs kref_get_unless_zero\n\nhci_conn::iso_data is accessed and modified without lock or RCU.\nThis leads to a race\n\n    [Task hdev->workqueue]                 \t[Task 2]\n    iso_recv                                    iso_conn_put(conn)\n      conn = LOAD hcon->iso_data                  iso_conn_free(conn)\n      iso_conn_hold_unless_zero(conn)               hcon->iso_data = NULL\n                                                    kfree(conn)\n        kref_get_unless_zero(&conn->ref) /* UAF */\n\nand also to races in iso_conn_add() vs. iso_conn_free().\n\nFix by adding spinlock hci_conn::proto_lock and using it to guard\nhci_conn::iso_data.\n\n## Affected\n\n- `Linux >= dc26097bdb864a0d5955b9a25e43376ffc1af99b < 876a3e94c70d0859d1dad1c986112d4f0d99eba8`\n- `Linux >= dc26097bdb864a0d5955b9a25e43376ffc1af99b < af24e338bf5dafb80f42baa9a0b9e9b57b1c5d9c`\n- `Linux f53e7489273dc2bb307bf50f319b3762d45534f0`\n- `Linux a58d0f5dac322e16cc75334d000666512341bde5`\n- `Linux >= 6.11.11 < 6.12`\n- `Linux >= 6.12.2 < 6.13`\n- `Linux 6.13`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}