{"id":"CVE-2026-74540","title":"Bluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp\n\nl2cap_le_connect_rsp() obtains a channel via\n__l2cap_get_chan_by_ident() but neither holds a reference nor uses\nl2cap…","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 >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 15d6c2367217a6a20b1abae9f38ded716bf620f1","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 1818180fe12d6cec7a437bc59cde8efdf6b10250","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 8325eafb38c3dee5af329266393763693d17381b","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < fd4c1e301bdec60a40728ea37de531cbccda501a","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 522b730c62c53a1981604fd73524697fd347830d","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 09f447accc2570751e7d17f0dc0788b40d3edade","Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < c4740e7f23ff9a8210198d8b4703259e21b9f69d","Linux 3.14"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T18:59:42.755795Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T19:05:54.604Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74540","references":[{"url":"https://git.kernel.org/stable/c/15d6c2367217a6a20b1abae9f38ded716bf620f1"},{"url":"https://git.kernel.org/stable/c/1818180fe12d6cec7a437bc59cde8efdf6b10250"},{"url":"https://git.kernel.org/stable/c/8325eafb38c3dee5af329266393763693d17381b"},{"url":"https://git.kernel.org/stable/c/fd4c1e301bdec60a40728ea37de531cbccda501a"},{"url":"https://git.kernel.org/stable/c/522b730c62c53a1981604fd73524697fd347830d"},{"url":"https://git.kernel.org/stable/c/58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136"},{"url":"https://git.kernel.org/stable/c/09f447accc2570751e7d17f0dc0788b40d3edade"},{"url":"https://git.kernel.org/stable/c/c4740e7f23ff9a8210198d8b4703259e21b9f69d"}],"tags":["cve.org"],"epss":0.00255,"epssPercentile":0.15954,"ingestedAt":"2026-10-16T19:46:24.344Z","slug":"CVE-2026-74540","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix UAF in l2cap_le_connect_rsp\n\nl2cap_le_connect_rsp() obtains a channel via\n__l2cap_get_chan_by_ident() but neither holds a reference nor uses\nl2cap_chan_hold_unless_zero() before locking and operating on it.\nA concurrent l2cap_chan_del() triggered by a remote disconnect can\nfree the channel between the lookup and l2cap_chan_lock(), causing\na use-after-free.\n\nThe BR/EDR counterpart l2cap_connect_rsp() and the sibling handler\nl2cap_le_command_rej() already use l2cap_chan_hold_unless_zero()\nto safely hold a reference, but l2cap_le_connect_rsp() was left\nunprotected.\n\nFix by adding l2cap_chan_hold_unless_zero() after the ident lookup\nand l2cap_chan_put() on the exit path, consistent with other L2CAP\nresponse handlers.\n\n## Affected\n\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 15d6c2367217a6a20b1abae9f38ded716bf620f1`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 1818180fe12d6cec7a437bc59cde8efdf6b10250`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 8325eafb38c3dee5af329266393763693d17381b`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < fd4c1e301bdec60a40728ea37de531cbccda501a`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 522b730c62c53a1981604fd73524697fd347830d`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 58e3c5289ad230a7e24ae4b0c7b43f5ee6e32136`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < 09f447accc2570751e7d17f0dc0788b40d3edade`\n- `Linux >= f1496dee9cbde2a62821f4441dadb0d3360f60c3 < c4740e7f23ff9a8210198d8b4703259e21b9f69d`\n- `Linux 3.14`\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":[]}