CVE-2026-89745Hinoki check available

Lockdown bypass via omitted mmap_prepare check

Published Sep 11, 2026 · Updated Sep 11, 2026

Improper access control in Linux 6.19 allows local users to bypass integrity-mode lockdown through a debugfs mmap operation. The debugfs_locked_down function checks mmap but omits mmap_prepare, so relayfs files using only mmap_prepare skip security_locked_down. An affected kernel must run in integrity mode with debugfs and a reachable mmap_prepare-backed file; bypassed debugfs access can expose or drive hardware.

CVSS severityUnavailable
Unscored
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper access control in Linux 6.19 allows local users to bypass integrity-mode lockdown through a debugfs mmap operation. The debugfs_locked_down function checks mmap but omits mmap_prepare, so relayfs files using only mmap_prepare skip security_locked_down. An affected kernel must run in integrity mode with debugfs and a reachable mmap_prepare-backed file; bypassed debugfs access can expose or drive hardware.

The record

CVE
CVE-2026-89745
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1211
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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=6.19
  2. Affected versionversion=651fdda8406d42a5004c5c79f269540a85d6a1ab <e7f6a6b5741d16fdac7adaecbe0fa52ae756f208
  3. Affected versionversion=651fdda8406d42a5004c5c79f269540a85d6a1ab <f81808de37338aac8e167f99bfae647b1b835c70

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.19; version=651fdda8406d42a5004c5c79f269540a85d6a1ab <e7f6a6b5741d16fdac7adaecbe0fa52ae756f208; version=651fdda8406d42a5004c5c79f269540a85d6a1ab <f81808de37338aac8e167f99bfae647b1b835c70

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1211Exploitation for Defense Evasion

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