GHSA-2C97-7QVF-WX4V

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success

l2cap_ecred_reconf_rsp() returns early on success without clearing chan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp, l2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident after a successful transaction to prevent the channel from matching subsequent responses with the recycled ident value.

A remote attacker that completed a reconfiguration as the peer can replay a failure response with the stale ident, causing the kernel to match and destroy the already-established channel via l2cap_chan_del(chan, ECONNRESET).

Clear chan->ident for all matching channels on success, and harden the failure path by using l2cap_chan_hold_unless_zero() consistent with other L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident).

Severity
8.8 (High)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-63976"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:16Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: l2cap: clear chan-\u003eident on ECRED reconfiguration success\n\nl2cap_ecred_reconf_rsp() returns early on success without clearing\nchan-\u003eident. Every other L2CAP response handler (l2cap_ecred_conn_rsp,\nl2cap_le_connect_rsp, l2cap_config_rsp) clears chan-\u003eident after a\nsuccessful transaction to prevent the channel from matching subsequent\nresponses with the recycled ident value.\n\nA remote attacker that completed a reconfiguration as the peer can\nreplay a failure response with the stale ident, causing the kernel to\nmatch and destroy the already-established channel via\nl2cap_chan_del(chan, ECONNRESET).\n\nClear chan-\u003eident for all matching channels on success, and harden the\nfailure path by using l2cap_chan_hold_unless_zero() consistent with\nother L2CAP handlers (l2cap_le_command_rej, __l2cap_get_chan_by_ident).",
  "id": "GHSA-2c97-7qvf-wx4v",
  "modified": "2026-07-20T15:31:53Z",
  "published": "2026-07-19T18:31:48Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63976"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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