CVE-2026-90186Public exploitHinoki check available

Kernel crash via shared-tag queue resize

Published Sep 17, 2026 · Updated Sep 17, 2026

NULL dereference in Linux 5.5 null_blk allows local users to crash the kernel by shrinking shared-tag queues through configfs. null_map_queues() retains module-wide queue counts after a per-device resize clears excess hardware-context slots, causing blk_mq_map_swqueue() to dereference a NULL context. The trigger requires administrative configfs access and an active null_blk device with shared_tags enabled; the disclosed consequence is a kernel crash.

CVSS severity4.4
Medium
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

NULL dereference in Linux 5.5 null_blk allows local users to crash the kernel by shrinking shared-tag queues through configfs. null_map_queues() retains module-wide queue counts after a per-device resize clears excess hardware-context slots, causing blk_mq_map_swqueue() to dereference a NULL context. The trigger requires administrative configfs access and an active null_blk device with shared_tags enabled; the disclosed consequence is a kernel crash.

The record

CVE
CVE-2026-90186
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 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=45919fbfe1c487c17ea1d198534339a5e8abeae3 <1cdfe2fa62b48728a9b436fbbd3dbe4c11593e24
  2. Affected versionversion=45919fbfe1c487c17ea1d198534339a5e8abeae3 <3e35ad503386a2e8a0e0460530dcbf421c79f6f2
  3. Affected versionversion=45919fbfe1c487c17ea1d198534339a5e8abeae3 <9c7bae099ddc92676ad1b7e29dd6c089e5f6196c
  4. Affected versionversion=45919fbfe1c487c17ea1d198534339a5e8abeae3 <baff300541a0012907cdde349728739fe16176d7
  5. Affected versionversion=45919fbfe1c487c17ea1d198534339a5e8abeae3 <f609f7bf9ce8c2fc427705c4a9f623a281239d06
  6. Affected versionversion=45919fbfe1c487c17ea1d198534339a5e8abeae3 <fcd53f3e8b758c79c3f2420d28a2a1dce6fda61a
  7. Affected versionversion=5.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=45919fbfe1c487c17ea1d198534339a5e8abeae3 <1cdfe2fa62b48728a9b436fbbd3dbe4c11593e24; version=45919fbfe1c487c17ea1d198534339a5e8abeae3 <3e35ad503386a2e8a0e0460530dcbf421c79f6f2; version=45919fbfe1c487c17ea1d198534339a5e8abeae3 <9c7bae099ddc92676ad1b7e29dd6c089e5f6196c; version=45919fbfe1c487c17ea1d198534339a5e8abeae3 <baff300541a0012907cdde349728739fe16176d7; version=45919fbfe1c487c17ea1d198534339a5e8abeae3 <f609f7bf9ce8c2fc427705c4a9f623a281239d06; version=45919fbfe1c487c17ea1d198534339a5e8abeae3 <fcd53f3e8b758c79c3f2420d28a2a1dce6fda61a; version=5.5

Published CVSS scores

4.4Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/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.

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No observations available

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

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

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Technologies

Your stack

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Your stack

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