CVE-2026-90094Hinoki check available

Tag-checking interference via leaked context-switch state

Published Sep 17, 2026 · Updated Sep 17, 2026

Context-switch state leakage in Linux 6.17 allows local users to affect another task's MTE mode via store-only tag checking. In arch/arm64/include/asm/processor.h, SCTLR_USER_MASK omits SCTLR_EL1.TCSO0, leaving the task-selected bit uncleared during context switches. The flaw requires arm64 MTE support and a task opting into store-only checks; the disclosed consequence is cross-task tag-checking state contamination.

CVSS severity2.5
Low
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Context-switch state leakage in Linux 6.17 allows local users to affect another task's MTE mode via store-only tag checking. In arch/arm64/include/asm/processor.h, SCTLR_USER_MASK omits SCTLR_EL1.TCSO0, leaving the task-selected bit uncleared during context switches. The flaw requires arm64 MTE support and a task opting into store-only checks; the disclosed consequence is cross-task tag-checking state contamination.

The record

CVE
CVE-2026-90094
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

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=4d51ff5bba00a13ca9b0b24883fa7adb07a167fc <00a73ce437e27fdc636a5ede445a4a491e01788d
  2. Affected versionversion=4d51ff5bba00a13ca9b0b24883fa7adb07a167fc <2f10bc3ff24c91657887901c3235b803e5055f2b
  3. Affected versionversion=4d51ff5bba00a13ca9b0b24883fa7adb07a167fc <b8f070ac3167595069feb1f794c127b805115645
  4. Affected versionversion=6.17

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4d51ff5bba00a13ca9b0b24883fa7adb07a167fc <00a73ce437e27fdc636a5ede445a4a491e01788d; version=4d51ff5bba00a13ca9b0b24883fa7adb07a167fc <2f10bc3ff24c91657887901c3235b803e5055f2b; version=4d51ff5bba00a13ca9b0b24883fa7adb07a167fc <b8f070ac3167595069feb1f794c127b805115645; version=6.17

Published CVSS scores

4.6TenableAV:L/AC:L/Au:S/C:N/I:N/A:C
5.5TenableCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
2.5Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N

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
Privilegesauthenticated
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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