CVE-2026-97523Network attack vector

Remote kernel fault via MPTCP scheduler race

Published Sep 25, 2026 · Updated Sep 25, 2026

Divide-by-zero in Linux kernel MPTCP scheduling allows remote attackers to trigger a kernel fault through a subflow state-change race. The mptcp_push_release function passes a zero mss_now value to tcp_push when transmission on a selected subflow fails after its socket state changes. Exploitation requires MPTCP traffic and precise timing between scheduler selection and the peer-driven state transition; the resulting fault can interrupt the host.

CVSS severityUnavailable
Unscored
EPSS probability0.67%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Get started

Summary

What happened

Divide-by-zero in Linux kernel MPTCP scheduling allows remote attackers to trigger a kernel fault through a subflow state-change race. The mptcp_push_release function passes a zero mss_now value to tcp_push when transmission on a selected subflow fails after its socket state changes. Exploitation requires MPTCP traffic and precise timing between scheduler selection and the peer-driven state transition; the resulting fault can interrupt the host.

The record

CVE
CVE-2026-97523
Published
Sep 25, 2026
Updated
Sep 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.15.190 <5.16
  2. Affected versionversion=5.19.4 <5.20
  3. Affected versionversion=6.0
  4. Affected versionversion=8caf5c15b5288d52d9c89374d6c10fa32ee84ec5
  5. Affected versionversion=c886d70286bf3ad411eb3d689328a67f7102c6ae <42064de57fb83231fcc89663a94885f228a1ee53
  6. Affected versionversion=c886d70286bf3ad411eb3d689328a67f7102c6ae <4c856f3c151a2f3fa237caa651c44015916ca584
  7. Affected versionversion=c886d70286bf3ad411eb3d689328a67f7102c6ae <8f11430d51ff8365bc51b670bc3002b65ae4c6b7
  8. Affected versionversion=c886d70286bf3ad411eb3d689328a67f7102c6ae <a09c87abf10a0a7e203137c75b5381aa63d9b31d
  9. Affected versionversion=fb9c73ef2ac2ec816efdc8b9267bc04e1369c20b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15.190 <5.16; version=5.19.4 <5.20; version=6.0; version=8caf5c15b5288d52d9c89374d6c10fa32ee84ec5; version=c886d70286bf3ad411eb3d689328a67f7102c6ae <42064de57fb83231fcc89663a94885f228a1ee53; version=c886d70286bf3ad411eb3d689328a67f7102c6ae <4c856f3c151a2f3fa237caa651c44015916ca584; version=c886d70286bf3ad411eb3d689328a67f7102c6ae <8f11430d51ff8365bc51b670bc3002b65ae4c6b7; version=c886d70286bf3ad411eb3d689328a67f7102c6ae <a09c87abf10a0a7e203137c75b5381aa63d9b31d; version=fb9c73ef2ac2ec816efdc8b9267bc04e1369c20b

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Get started to see how Hinoki identifies affected software and validates exploitability in your environment.

Get started