{"id":"CVE-2026-98108","summary":"Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan\n\nl2cap_new_connection() sets default value of channel mode to match the\nparent channel.  l2cap_le_connect_req() left this at the default, and\ncreated L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that\nmode.  This causes FLAG_DEFER_SETUP channels to reply to\nL2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect.\n\nIt can also result to stack OOB write (of l2cap_alloc_cid determined\nvalues) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not\nlimit maximum number of deferred channels or check for duplicate ident.\n\nFix by setting chan-\u003emode correctly in l2cap_le_connect_req().\n\nAlso check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE\ninstead of OOB write to make it less brittle.","modified":"2026-10-09T17:26:56.431017739Z","published":"2026-09-25T10:35:56.935Z","related":["openSUSE-SU-2026:12074-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98108.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0e1fc7cab95ad958e55d70a5dfaaea687c9c639f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/1074bcc57f741223f9fa82ce6afe5c3d783e4d10"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4ef05db5b08b176a551b4a6287372045998806b0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/564ae0e05e598aa895b9dbd18cb7d6eb64752869"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6cb79e6499228cfdbd4b3301371ce74d01cd2f80"},{"type":"WEB","url":"https://git.kernel.org/stable/c/aab17938998b29e75c3324763411aef3e300fc67"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ad0f44a3f1f688558ed876a0702bc2c82b0df689"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98108.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98108"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"15f02b91056253e8cdc592888f431da0731337b8"},{"fixed":"ad0f44a3f1f688558ed876a0702bc2c82b0df689"},{"fixed":"564ae0e05e598aa895b9dbd18cb7d6eb64752869"},{"fixed":"aab17938998b29e75c3324763411aef3e300fc67"},{"fixed":"0e1fc7cab95ad958e55d70a5dfaaea687c9c639f"},{"fixed":"1074bcc57f741223f9fa82ce6afe5c3d783e4d10"},{"fixed":"5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1"},{"fixed":"6cb79e6499228cfdbd4b3301371ce74d01cd2f80"},{"fixed":"4ef05db5b08b176a551b4a6287372045998806b0"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98108.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.7.0"},{"fixed":"5.10.271"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.222"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.189"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.158"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.111"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.53"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.7"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-98108.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}]}