CVE-2026-63976 (GCVE-0-2026-63976)

Vulnerability from cvelistv5 – Published: 2026-07-19 14:56 – Updated: 2026-07-20 13:42
VLAI
Title
Bluetooth: l2cap: clear chan->ident on ECRED reconfiguration success
Summary
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
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 59f5ecf6ad5c4db6ae81965a96156954a3b0d89a (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < ae0152d77d101c920769934fb102b18de0c6f526 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < c2afd2613fda90107c5e2fe8e855627451749c78 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < cc2b4f749de09975bfa06e58bbbad2f6acd4c79c (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 3b5b5f423b4fd23404a393bda8adba3cd6f74ef1 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < f39049304ba655ffcbb92edbdf8c51a1f1210bed (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 8e7977afaef37c6bd2b2654f1bce6ab40d471147 (git)
Affected: 15f02b91056253e8cdc592888f431da0731337b8 , < 00e1950716c6ed67d74777b2db286b0fa23b4be9 (git)
Create a notification for this product.
Linux Linux Affected: 5.7
Unaffected: 0 , < 5.7 (semver)
Unaffected: 5.10.259 , ≤ 5.10.* (semver)
Unaffected: 5.15.210 , ≤ 5.15.* (semver)
Unaffected: 6.1.176 , ≤ 6.1.* (semver)
Unaffected: 6.6.143 , ≤ 6.6.* (semver)
Unaffected: 6.12.93 , ≤ 6.12.* (semver)
Unaffected: 6.18.35 , ≤ 6.18.* (semver)
Unaffected: 7.0.12 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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Show details on NVD website
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{
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      "descriptions": [
        {
          "lang": "en",
          "value": "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)."
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            "version": "3.1"
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        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        {
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      ],
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    "cveId": "CVE-2026-63976",
    "datePublished": "2026-07-19T14:56:01.284Z",
    "dateReserved": "2026-07-19T07:54:57.024Z",
    "dateUpdated": "2026-07-20T13:42:00.067Z",
    "state": "PUBLISHED"
  },
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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, 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    "redhat_vex": {
      "current_release_date": "2026-07-21T16:35:50+00:00",
      "cve": "CVE-2026-63976",
      "id": "CVE-2026-63976",
      "initial_release_date": "2026-07-19T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Bluetooth: l2cap: clear chan-\u003eident on ECRED reconfiguration success",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-63976.json",
      "version": "3"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.