CVE-2026-97523
📛 CVE Title
mptcp: close race between scheduler and state change
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: close race between scheduler and state change The mptcp scheduler may race with subflow sockets state change: data transmission on the selected socket may fail and a later release could try to use mss_now reset to 0 for a divide operation. Address the issue by explicitly checking for the critical scenario.
Overview
- State
- PUBLISHED
- Assigner (CNA)
- Linux
- CVSS severity
- HIGH
- CVSS score
- 7.5 / 10
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Effective score
- 7.5 / 10 HIGH source: CNA overview
- CWE(s)
- —
- Reserved
- 2026-09-24
- Published
- 2026-09-25 10:21 UTC
- Last updated
- 2026-09-25 14:41 UTC
- Source
- https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/97xxx/CVE-2026-97523.json
- Linked Threat
- CVE-2026-97523 — mptcp: close race between scheduler and state change
NVD triage scoring NVD CVE 2.0
Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.
- NVD published
- 2026-09-25 11:17:02 UTC
- NVD last modified
- 2026-09-25 15:17:57 UTC
- NVD CVSS v3.1
- 7.5 / 10 HIGH source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- Exploitability subscore
- 3.9 / 10
- Impact subscore
- 3.6 / 10
NVD / KEV / EPSS data refreshed 2026-09-26 04:35 UTC. Re-run the 🛰 Backfill from NVD button above to refresh.
Affected products (2)
| Vendor | Product | Versions | Platforms |
|---|---|---|---|
| Linux | Linux |
c886d70286bf3ad411eb3d689328a67f7102c6ae (affected),
c886d70286bf3ad411eb3d689328a67f7102c6ae (affected),
c886d70286bf3ad411eb3d689328a67f7102c6ae (affected),
c886d70286bf3ad411eb3d689328a67f7102c6ae (affected),
fb9c73ef2ac2ec816efdc8b9267bc04e1369c20b (affected),
8caf5c15b5288d52d9c89374d6c10fa32ee84ec5 (affected),
5.15.190 (affected),
5.19.4 (affected)
|
— |
| Linux | Linux |
6.0 (affected),
0 (unaffected),
6.12.111 (unaffected),
6.18.53 (unaffected),
7.2.7 (unaffected),
7.3-rc4 (unaffected)
|
— |
Vendor references (4)
References embedded in the original CVE record by the assigning CNA.
Web references (0)
DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.
No web references attached yet.
NVD-tagged references (4)
Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.
- https://git.kernel.org/stable/c/42064de57fb83231fcc89663a94885f228a1ee53 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/4c856f3c151a2f3fa237caa651c44015916ca584 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/8f11430d51ff8365bc51b670bc3002b65ae4c6b7 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- https://git.kernel.org/stable/c/a09c87abf10a0a7e203137c75b5381aa63d9b31d 416baaa9-dc9f-4396-8d5f-8c081fb06d67
AI Forensic Analysis
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Raw JSON
The full cvelistV5 record. Download as CVE-2026-97523.json.
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/mptcp/protocol.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "8f11430d51ff8365bc51b670bc3002b65ae4c6b7",
"status": "affected",
"version": "c886d70286bf3ad411eb3d689328a67f7102c6ae",
"versionType": "git"
},
{
"lessThan": "a09c87abf10a0a7e203137c75b5381aa63d9b31d",
"status": "affected",
"version": "c886d70286bf3ad411eb3d689328a67f7102c6ae",
"versionType": "git"
},
{
"lessThan": "4c856f3c151a2f3fa237caa651c44015916ca584",
"status": "affected",
"version": "c886d70286bf3ad411eb3d689328a67f7102c6ae",
"versionType": "git"
},
{
"lessThan": "42064de57fb83231fcc89663a94885f228a1ee53",
"status": "affected",
"version": "c886d70286bf3ad411eb3d689328a67f7102c6ae",
"versionType": "git"
},
{
"status": "affected",
"version": "fb9c73ef2ac2ec816efdc8b9267bc04e1369c20b",
"versionType": "git"
},
{
"status": "affected",
"version": "8caf5c15b5288d52d9c89374d6c10fa32ee84ec5",
"versionType": "git"
},
{
"lessThan": "5.16",
"status": "affected",
"version": "5.15.190",
"versionType": "semver"
},
{
"lessThan": "5.20",
"status": "affected",
"version": "5.19.4",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"net/mptcp/protocol.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.0"
},
{
"lessThan": "6.0",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.111",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc4",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.111",
"versionStartIncluding": "6.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.53",
"versionStartIncluding": "6.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.7",
"versionStartIncluding": "6.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc4",
"versionStartIncluding": "6.0",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.15.190",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "5.19.4",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: close race between scheduler and state change\n\nThe mptcp scheduler may race with subflow sockets state change: data\ntransmission on the selected socket may fail and a later release could\ntry to use mss_now reset to 0 for a divide operation.\n\nAddress the issue by explicitly checking for the critical scenario."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.5,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - mptcp_push_release is reached from __mptcp_push_pending after mptcp_sched_get_send. A remote MPTCP peer changes the selected subflow's sk_state via TCP RST/FIN (tcp_v4_rcv/tcp_rcv_established/tcp_reset) without the msk lock, and a DSS DATA_ACK (mptcp_incoming_options\u2192ack_update_msk) sets MPTCP_PUSH_PENDING so mptcp_release_cb calls that push.\nAC:L - The attacker creates both halves of the race: they induce __mptcp_push_pending (DSS DATA_ACK, or eliciting mptcp_sendmsg) so mptcp_subflow_get_send snapshots __tcp_can_send without the ssk lock, then RST/FIN/MP_FAIL that subflow before lock_sock; the window is attacker-timed and retryable, not an uninfluencable layout.\nPR:N - Completing MP_CAPABLE to an IPPROTO_MPTCP listener needs no account or capability; net.mptcp.enabled defaults to 1 in mptcp pernet init, and tcp_rcv_established/mptcp_incoming_options apply no application credentials before the DATA_ACK and RST/FIN that cause this race.\nUI:N - The attacker sends the DATA_ACK and RST/FIN themselves and supplies the request that makes the service call mptcp_sendmsg; no victim mount, click, or extra confirmation is required.\nS:U - The divide-error runs in tcp_tso_autosize/tcp_set_skb_tso_segs on the host kernel MPTCP/TCP socket; it does not cross a VM, IOMMU, or sandbox boundary.\nC:N - When __tcp_can_send fails in mptcp_sendmsg_frag, info->mss_now stays 0 and tcp_push divides by zero; that CPU exception does not read freed objects or out-of-range kernel memory.\nI:N - tcp_write_xmit aborts on the divide in tcp_tso_autosize/tcp_set_skb_tso_segs before modifying TCP control blocks or packet contents; this is not an OOB/UAF write or control-flow hijack.\nA:H - bytes/mss_now in tcp_tso_autosize and DIV_ROUND_UP(skb->len, mss_now) in tcp_set_skb_tso_segs raise a kernel divide-error oops/panic from mptcp_push_release, and the attacker can repeat it across MPTCP connections."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-25T14:41:04.318Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/8f11430d51ff8365bc51b670bc3002b65ae4c6b7"
},
{
"url": "https://git.kernel.org/stable/c/a09c87abf10a0a7e203137c75b5381aa63d9b31d"
},
{
"url": "https://git.kernel.org/stable/c/4c856f3c151a2f3fa237caa651c44015916ca584"
},
{
"url": "https://git.kernel.org/stable/c/42064de57fb83231fcc89663a94885f228a1ee53"
}
],
"title": "mptcp: close race between scheduler and state change",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-97523",
"datePublished": "2026-09-25T10:21:27.042Z",
"dateReserved": "2026-09-24T16:01:01.152Z",
"dateUpdated": "2026-09-25T14:41:04.318Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}