CVE-2026-89785

Kernel out-of-bounds read via undersized INDEX_ROOT

Published Sep 16, 2026 · Updated Sep 16, 2026

Out-of-bounds reads in Linux ntfs3 5.15 allow local users with CAP_SYS_ADMIN to trigger an invalid kernel read by mounting a crafted NTFS image. ntfs_reparse_init() and ntfs_objid_init() accept zero-length resident $R or $O INDEX_ROOT attributes, and resident_data() returns an end-of-record pointer whose type or rule field is then read. The gate is CAP_SYS_ADMIN and a crafted-image mount; published evidence demonstrates a KASAN-detected read but no data disclosure or production-kernel crash.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds reads in Linux ntfs3 5.15 allow local users with CAP_SYS_ADMIN to trigger an invalid kernel read by mounting a crafted NTFS image. ntfs_reparse_init() and ntfs_objid_init() accept zero-length resident $R or $O INDEX_ROOT attributes, and resident_data() returns an end-of-record pointer whose type or rule field is then read. The gate is CAP_SYS_ADMIN and a crafted-image mount; published evidence demonstrates a KASAN-detected read but no data disclosure or production-kernel crash.

The record

CVE
CVE-2026-89785
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

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=5.15
  2. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <2064bc663f89e61b8681c1fb9d1ce445de72063d
  3. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <64bb6000bfbdf241a6dd578199acd90321a4243e
  4. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <66c074eab6f966fbe48a0fc4b3a45b2a2e2df527
  5. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <72caafbc95c5dca8266a942b8e96ad81d8d9adc7
  6. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <94fce1d3e74fe011e21f17490ba58491709fd7e5
  7. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <bd631e2005290a55c8edda87363bc0d594c01705
  8. Affected versionversion=82cae269cfa953032fbb8980a7d554d60fb00b17 <eb80003744e32a7366a523015e4acfe0a2ac7d88

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.15; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <2064bc663f89e61b8681c1fb9d1ce445de72063d; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <64bb6000bfbdf241a6dd578199acd90321a4243e; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <66c074eab6f966fbe48a0fc4b3a45b2a2e2df527; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <72caafbc95c5dca8266a942b8e96ad81d8d9adc7; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <94fce1d3e74fe011e21f17490ba58491709fd7e5; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <bd631e2005290a55c8edda87363bc0d594c01705; version=82cae269cfa953032fbb8980a7d554d60fb00b17 <eb80003744e32a7366a523015e4acfe0a2ac7d88

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

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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
Privilegesadmin
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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