CVE-2026-23157

System hang via skipped Btrfs metadata writeback

Published Feb 14, 2026 · Updated Feb 14, 2026

Denial of service in Linux Kernel before 6.18.9 allows local users to hang the system by dirtying Btrfs metadata in a constrained cgroup. btree_writepages skips metadata writeback while the Btrfs btree inode holds less than 32 MiB of dirty data, even when cgroup throttling requires those pages to be flushed. Triggering the deadlock requires a memory-limited cgroup whose dirty limit is below that threshold; affected tasks remain blocked in balance_dirty_pages.

CVSS severity5.5
Medium
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

Denial of service in Linux Kernel before 6.18.9 allows local users to hang the system by dirtying Btrfs metadata in a constrained cgroup. btree_writepages skips metadata writeback while the Btrfs btree inode holds less than 32 MiB of dirty data, even when cgroup throttling requires those pages to be flushed. Triggering the deadlock requires a memory-limited cgroup whose dirty limit is below that threshold; affected tasks remain blocked in balance_dirty_pages.

The record

CVE
CVE-2026-23157
Published
Feb 14, 2026
Updated
Feb 14, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e159150a9a56d66d247f4b5510bed46fe58aa1c
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <629666d20c7dcd740e193ec0631fdff035b1f7d6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e159150a9a56d66d247f4b5510bed46fe58aa1c; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <629666d20c7dcd740e193ec0631fdff035b1f7d6

Published CVSS scores

5.5NIST NVDCVSS: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.

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

CWE-667Improper Locking
T1499.004Application or System Exploitation

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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