FKIE_CVE-2026-63976

Vulnerability from fkie_nvd - Published: 2026-07-19 16:17 - Updated: 2026-07-20 15:16
Severity
8.8 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
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).
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "59f5ecf6ad5c4db6ae81965a96156954a3b0d89a",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "ae0152d77d101c920769934fb102b18de0c6f526",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "c2afd2613fda90107c5e2fe8e855627451749c78",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "cc2b4f749de09975bfa06e58bbbad2f6acd4c79c",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "3b5b5f423b4fd23404a393bda8adba3cd6f74ef1",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "f39049304ba655ffcbb92edbdf8c51a1f1210bed",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "8e7977afaef37c6bd2b2654f1bce6ab40d471147",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            },
            {
              "lessThan": "00e1950716c6ed67d74777b2db286b0fa23b4be9",
              "status": "affected",
              "version": "15f02b91056253e8cdc592888f431da0731337b8",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.7"
            },
            {
              "lessThan": "5.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.93",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.35",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.12",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "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)."
    }
  ],
  "id": "CVE-2026-63976",
  "lastModified": "2026-07-20T15:16:59.830",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T16:17:16.733",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/00e1950716c6ed67d74777b2db286b0fa23b4be9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3b5b5f423b4fd23404a393bda8adba3cd6f74ef1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/59f5ecf6ad5c4db6ae81965a96156954a3b0d89a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8e7977afaef37c6bd2b2654f1bce6ab40d471147"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ae0152d77d101c920769934fb102b18de0c6f526"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c2afd2613fda90107c5e2fe8e855627451749c78"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc2b4f749de09975bfa06e58bbbad2f6acd4c79c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f39049304ba655ffcbb92edbdf8c51a1f1210bed"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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