CVE-2026-89959

Guest control-domain retention via inverted bitmap operation

Published Sep 16, 2026 · Updated Sep 16, 2026

Improper control-domain removal in Linux allows guest OS users to retain control domains removed from an s390 KVM guest. vfio_ap_mdev_cfg_remove applies bitmap_andnot to the removed-domain and assigned-domain masks, selecting removed but unassigned domains instead of their intersection. The condition requires an s390 KVM guest using a vfio_ap mediated device; a removed control domain remains available for guest AP commands.

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

What happened

Improper control-domain removal in Linux allows guest OS users to retain control domains removed from an s390 KVM guest. vfio_ap_mdev_cfg_remove applies bitmap_andnot to the removed-domain and assigned-domain masks, selecting removed but unassigned domains instead of their intersection. The condition requires an s390 KVM guest using a vfio_ap mediated device; a removed control domain remains available for guest AP commands.

The record

CVE
CVE-2026-89959
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=6.0
  2. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <02e72909453dee2f8a09f78819f9a9cb902dfbdc
  3. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <12871a4269f139221c9fde9ea3eb69c9228f59d4
  4. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <2ff68bf414de167bc138e6e211ee1ad3ab3c5052
  5. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <4bffadde7fc49b00493fb78c6376f958998d4b8c
  6. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <6b8a02e216f6b520cc029e43ddc83956605135d5
  7. Affected versionversion=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <f7d66afc34bc6e833c8ebe56973afec35f473bc1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.0; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <02e72909453dee2f8a09f78819f9a9cb902dfbdc; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <12871a4269f139221c9fde9ea3eb69c9228f59d4; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <2ff68bf414de167bc138e6e211ee1ad3ab3c5052; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <4bffadde7fc49b00493fb78c6376f958998d4b8c; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <6b8a02e216f6b520cc029e43ddc83956605135d5; version=eeb386aeb5b7c8d2dae6a3ba49255d8a97803182 <f7d66afc34bc6e833c8ebe56973afec35f473bc1

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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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