CVE-2026-89600

Stale stack disclosure via dangling fanotify range pointer

Published Sep 11, 2026 · Updated Sep 11, 2026

Use-after-free in Linux 6.14 fanotify permission events allows local users to read a stale file offset from kernel stack memory. fanotify_alloc_perm_event() retains a pointer to a triggering task's stack-backed range.pos, which copy_range_info_to_user() dereferences after cancellation unwinds that stack frame. Reachability requires a CAP_SYS_ADMIN fanotify listener, a permission event, and the cancellation race; disclosure is limited to the stale eight-byte offset.

CVSS severityUnavailable
Unscored
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Linux 6.14 fanotify permission events allows local users to read a stale file offset from kernel stack memory. fanotify_alloc_perm_event() retains a pointer to a triggering task's stack-backed range.pos, which copy_range_info_to_user() dereferences after cancellation unwinds that stack frame. Reachability requires a CAP_SYS_ADMIN fanotify listener, a permission event, and the cancellation race; disclosure is limited to the stale eight-byte offset.

The record

CVE
CVE-2026-89600
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
Unavailable

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

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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=6.14
  2. Affected versionversion=870499bc1d4dc04cba1f63dd5e7bc02b983e2458 <66aa9a9e6481bfa512ee5b6380eaaec455a954d2
  3. Affected versionversion=870499bc1d4dc04cba1f63dd5e7bc02b983e2458 <b8f73b163b646bc56d4dce9c697a578e333f4894
  4. Affected versionversion=870499bc1d4dc04cba1f63dd5e7bc02b983e2458 <d7f1cf5be33ef0175a4e8ed8687aeb98fb00a851

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=6.14; version=870499bc1d4dc04cba1f63dd5e7bc02b983e2458 <66aa9a9e6481bfa512ee5b6380eaaec455a954d2; version=870499bc1d4dc04cba1f63dd5e7bc02b983e2458 <b8f73b163b646bc56d4dce9c697a578e333f4894; version=870499bc1d4dc04cba1f63dd5e7bc02b983e2458 <d7f1cf5be33ef0175a4e8ed8687aeb98fb00a851

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.

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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
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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