CVE-2026-31455

Kernel state corruption via XFS unmount race

Published Apr 22, 2026 · Updated Apr 22, 2026

Race condition in the XFS unmount path in Linux Kernel allows local users with CAP_SYS_ADMIN to corrupt kernel state during unmount. xfs_unmount_flush_inodes() pushes the active item list before inodegc and background reclaim stop, allowing inodegc to add dirty inodes while reclaim aborts and frees them. Exploitation requires CAP_SYS_ADMIN in the initial user namespace and control of an XFS mount; no remote path or unprivileged user-namespace path is reported.

CVSS severity7.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the XFS unmount path in Linux Kernel allows local users with CAP_SYS_ADMIN to corrupt kernel state during unmount. xfs_unmount_flush_inodes() pushes the active item list before inodegc and background reclaim stop, allowing inodegc to add dirty inodes while reclaim aborts and frees them. Exploitation requires CAP_SYS_ADMIN in the initial user namespace and control of an XFS mount; no remote path or unprivileged user-namespace path is reported.

The record

CVE
CVE-2026-31455
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 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=5.9
  2. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <239d734c00644072862fa833805c4471573b1445
  3. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <4f24a767e3d64a5f58c595b5c29b6063a201f1e3
  4. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <558e3275d8a3b101be18a7fe7d1634053e9d9b07
  5. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <8147e304d7d32fd5c3e943babc296ce2873dc279
  6. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <a89434a6188d8430ea31120da96e3e4cefb58686
  7. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <bda27fc0b4eb3a425d9a18475c4cb94fbe862c60
  8. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <d38135af04a3ad8a585c899d176efc8e97853115
  9. Affected versionversion=90c60e16401248a4900f3f9387f563d0178dcf34 <e6cc490048f78b009259a5f032acead9f789c34c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.9; version=90c60e16401248a4900f3f9387f563d0178dcf34 <239d734c00644072862fa833805c4471573b1445; version=90c60e16401248a4900f3f9387f563d0178dcf34 <4f24a767e3d64a5f58c595b5c29b6063a201f1e3; version=90c60e16401248a4900f3f9387f563d0178dcf34 <558e3275d8a3b101be18a7fe7d1634053e9d9b07; version=90c60e16401248a4900f3f9387f563d0178dcf34 <8147e304d7d32fd5c3e943babc296ce2873dc279; version=90c60e16401248a4900f3f9387f563d0178dcf34 <a89434a6188d8430ea31120da96e3e4cefb58686; version=90c60e16401248a4900f3f9387f563d0178dcf34 <bda27fc0b4eb3a425d9a18475c4cb94fbe862c60; version=90c60e16401248a4900f3f9387f563d0178dcf34 <d38135af04a3ad8a585c899d176efc8e97853115; version=90c60e16401248a4900f3f9387f563d0178dcf34 <e6cc490048f78b009259a5f032acead9f789c34c

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

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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