CVE-2026-63976
Full vulnerability record from the local CVENow database.
Description
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
HIGH
CVSS score
8.8
(v3.1)
Vulnerability status
Undergoing Analysis
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19 16:17:16.733000
Last modified
2026-10-19 21:17:15.263000
View original CVE JSON
{
"id": "CVE-2026-63976",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-07-19T16:17:16.733",
"lastModified": "2026-10-19T21:17:15.263",
"vulnStatus": "Undergoing Analysis",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: l2cap: clear chan->ident on ECRED reconfiguration success\n\nl2cap_ecred_reconf_rsp() returns early on success without clearing\nchan->ident. Every other L2CAP response handler (l2cap_ecred_conn_rsp,\nl2cap_le_connect_rsp, l2cap_config_rsp) clears chan->ident 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->ident 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)."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/bluetooth/l2cap_core.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
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"defaultStatus": "affected",
"programFiles": [
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"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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{
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{
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},
{
"version": "5.10.259",
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},
{
"version": "5.15.210",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.176",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.143",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.93",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.35",
"lessThanOrEqual": "6.18.*",
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},
{
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},
{
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"versionType": "original_commit_for_fix",
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}
]
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]
}
],
"metrics": {
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{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
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"vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 8.8,
"baseSeverity": "HIGH",
"attackVector": "ADJACENT_NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.8,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T15:34:26.280157Z",
"id": "CVE-2026-63976",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
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"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-694"
}
]
}
],
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