{"id":"CVE-2026-98108","title":"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","summary":"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_co…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < ad0f44a3f1f688558ed876a0702bc2c82b0df689","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 564ae0e05e598aa895b9dbd18cb7d6eb64752869","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < aab17938998b29e75c3324763411aef3e300fc67","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 0e1fc7cab95ad958e55d70a5dfaaea687c9c639f","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 1074bcc57f741223f9fa82ce6afe5c3d783e4d10","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 6cb79e6499228cfdbd4b3301371ce74d01cd2f80","Linux >= 15f02b91056253e8cdc592888f431da0731337b8 < 4ef05db5b08b176a551b4a6287372045998806b0","Linux 5.7"],"published":"2026-09-25","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:18:32.780","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98108","references":[{"url":"https://git.kernel.org/stable/c/0e1fc7cab95ad958e55d70a5dfaaea687c9c639f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/1074bcc57f741223f9fa82ce6afe5c3d783e4d10","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4ef05db5b08b176a551b4a6287372045998806b0","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/564ae0e05e598aa895b9dbd18cb7d6eb64752869","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6cb79e6499228cfdbd4b3301371ce74d01cd2f80","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/aab17938998b29e75c3324763411aef3e300fc67","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ad0f44a3f1f688558ed876a0702bc2c82b0df689","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00242,"epssPercentile":0.15284,"ingestedAt":"2026-09-25T11:06:38.825Z","slug":"CVE-2026-98108","body":"## Overview\n\nIn 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->mode 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":210902,"id":"CVE-2026-98108","ts":1790349114232,"field":"cvss","old":null,"new":"7.5"},{"seq":210901,"id":"CVE-2026-98108","ts":1790349114232,"field":"severity","old":"none","new":"high"}]}