CVE-2026-89922

Host use-after-free via unlocked memslot access

Published Sep 16, 2026 · Updated Sep 16, 2026

Use-after-free in Linux KVM s390 allows attackers to trigger unsafe host memory access during concurrent watchpoint and memslot updates. The __import_wp_info() path calls kvm_read_guest() without holding kvm->srcu or slots_lock, allowing a concurrent update to free the memslots array while it remains in use. Reachability requires an s390 KVM guest-debug watchpoint import to overlap a host memslot update; published sources report no demonstrated crash or code-execution outcome.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
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.

Book a demo

Summary

What happened

Use-after-free in Linux KVM s390 allows attackers to trigger unsafe host memory access during concurrent watchpoint and memslot updates. The __import_wp_info() path calls kvm_read_guest() without holding kvm->srcu or slots_lock, allowing a concurrent update to free the memslots array while it remains in use. Reachability requires an s390 KVM guest-debug watchpoint import to overlap a host memslot update; published sources report no demonstrated crash or code-execution outcome.

The record

CVE
CVE-2026-89922
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
Unavailable
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

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=27291e2165b6de70c476b7b675308113edd69a60 <4c05bf21d1806853e662cc19e744736a3408f155
  2. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <6830fbc3724bf49c142aae69a4694f115fa9cedd
  3. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <76f5b4ea9ed0aa5a34bda9d8a878f2c73026ec03
  4. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <a4e482def8533ebace517d9f67f1465841b1f982
  5. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <cc710ee45395efb4937e042960f791d33924e5f6
  6. Affected versionversion=27291e2165b6de70c476b7b675308113edd69a60 <f8e3a9997d5ecd56ebe4b262ff424516c068fecb
  7. Affected versionversion=3.16

What conditions does exploitation require?

Attack vectorUnavailable in this record.
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=27291e2165b6de70c476b7b675308113edd69a60 <4c05bf21d1806853e662cc19e744736a3408f155; version=27291e2165b6de70c476b7b675308113edd69a60 <6830fbc3724bf49c142aae69a4694f115fa9cedd; version=27291e2165b6de70c476b7b675308113edd69a60 <76f5b4ea9ed0aa5a34bda9d8a878f2c73026ec03; version=27291e2165b6de70c476b7b675308113edd69a60 <a4e482def8533ebace517d9f67f1465841b1f982; version=27291e2165b6de70c476b7b675308113edd69a60 <cc710ee45395efb4937e042960f791d33924e5f6; version=27291e2165b6de70c476b7b675308113edd69a60 <f8e3a9997d5ecd56ebe4b262ff424516c068fecb; 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.

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

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
VectorUnavailable
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo