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CVE-2026-98108

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan l2cap_new_connection() sets default value of channel mode to match the parent channel. l2cap_le_connect_req() left this at the default, and created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that mode. This causes FLAG_DEFER_SETUP channels to reply to L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect. It can also result to stack OOB write (of l2cap_alloc_cid determined values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not limit maximum number of deferred channels or check for duplicate ident. Fix by setting chan->mode correctly in l2cap_le_connect_req(). Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE instead of OOB write to make it less brittle.

Severity
HIGH
CVSS score
7.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-09-25 11:17:41.863000
Last modified
2026-11-12 18:27:45.737000
View original CVE JSON 
{
  "id": "CVE-2026-98108",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:41.863",
  "lastModified": "2026-11-12T18:27:45.737",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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->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."
    }
  ],
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        "type": "Secondary",
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          "vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
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        "exploitabilityScore": 1.6,
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  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
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