CVE-2026-89926

Kernel warning via truncated watchpoint allocation length

Published Sep 16, 2026 · Updated Sep 16, 2026

Integer truncation in Linux KVM s390 allows local users to trigger a kernel warning through an oversized guest watchpoint length. __import_wp_info() validates the length after narrowing it from 64 bits to int but allocates memory using the original untruncated value. Access to the KVM s390 guest-debug interface is required; the request causes a failed allocation and warning, which becomes a panic only under configured warning policy.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

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Summary

What happened

Integer truncation in Linux KVM s390 allows local users to trigger a kernel warning through an oversized guest watchpoint length. __import_wp_info() validates the length after narrowing it from 64 bits to int but allocates memory using the original untruncated value. Access to the KVM s390 guest-debug interface is required; the request causes a failed allocation and warning, which becomes a panic only under configured warning policy.

The record

CVE
CVE-2026-89926
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <3fe801db90bdeefb0bbdda42d832846b53f64f8a
  2. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <4c07680a467e2f7697245bcd11691bffb2a6f0ed
  3. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <71153d3262517e1c02c3a66aa5094f279b2d1454
  4. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <aef540194effd768bed0bd2e6a74fe135a3d7c3a
  5. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <b94ab9caa5d72c78226121cccff5e33f946da900
  6. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <beb9c55af609c4c7308259d7191688c75a4e3d4a
  7. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <fec89d327d9b2b669b5bbdac209386c6317c3722
  8. Affected versionversion=3.16

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=27291e2165b6de70c476b7b675308113edd69a60 <3fe801db90bdeefb0bbdda42d832846b53f64f8a; version=27291e2165b6de70c476b7b675308113edd69a60 <4c07680a467e2f7697245bcd11691bffb2a6f0ed; version=27291e2165b6de70c476b7b675308113edd69a60 <71153d3262517e1c02c3a66aa5094f279b2d1454; version=27291e2165b6de70c476b7b675308113edd69a60 <aef540194effd768bed0bd2e6a74fe135a3d7c3a; version=27291e2165b6de70c476b7b675308113edd69a60 <b94ab9caa5d72c78226121cccff5e33f946da900; version=27291e2165b6de70c476b7b675308113edd69a60 <beb9c55af609c4c7308259d7191688c75a4e3d4a; version=27291e2165b6de70c476b7b675308113edd69a60 <fec89d327d9b2b669b5bbdac209386c6317c3722; version=3.16

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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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