CVE-2026-90154Network attack vector

Connection interruption via cross-session state changes

Published Sep 17, 2026 · Updated Sep 17, 2026

Session-state corruption in Linux ksmbd allows remote authenticated users to interrupt SMB connections via logoff requests. The ksmbd_all_conn_set_status() function mistakes a transient binding flag for target-session membership and writes connection status without protecting closing states against concurrent updates. Exposure requires an active ksmbd server and overlapping session binding; unrelated connections are forced to reconnect or repeat session setup, with no documented kernel crash.

CVSS severity4.2

Medium

EPSS probability0.21%

Next 30 days · Oct 19, 2026

Known exploitationUnconfirmed

Based on sourced intelligence

Hinoki checkNot available

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Summary

What happened

The record

CVE: CVE-2026-90154
Published: Sep 17, 2026
Updated: Sep 17, 2026

Vendor: The Linux Kernel Organization
Product: Linux
Classifications: T1499

Attack vector: network
Privileges: authenticated

Timeline

How it unfolded

Sep 17, 2026CVE publishedPublication date reported by the CVE source.
Sep 17, 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.

Affected versionversion=5.15
Affected versionversion=f5a544e3bab78142207e0242d22442db85ba1eff <0875872718b98e8530fbc634e5aa7dbd3253b80d
Affected versionversion=f5a544e3bab78142207e0242d22442db85ba1eff <c50e628122aed077695669e25b842e778511a43d

What conditions does exploitation require?

Attack vectornetwork

Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=f5a544e3bab78142207e0242d22442db85ba1eff <0875872718b98e8530fbc634e5aa7dbd3253b80d; version=f5a544e3bab78142207e0242d22442db85ba1eff <c50e628122aed077695669e25b842e778511a43d

Published CVSS scores

6.5Tenable NessusCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:U/RC:C

7.1Tenable NessusCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

4.2Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L

5.6TenableAV:L/AC:L/Au:N/C:N/I:P/A:C

6.3TenableCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H

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

Privilegesauthenticated

Known exploitationUnconfirmed

Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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

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Your stack

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