CVE-2024-26726

Kernel crash via dropped free-space extent map

Published Apr 3, 2024 · Updated May 11, 2026

Reachable assertion in affected Linux kernel releases allows local users to crash the kernel after a Btrfs free-space-cache write fails. The first failed write drops the special free-space inode's extent map; a retry searches the commit root, receives EXTENT_MAP_HOLE, and reaches an assertion in __extent_writepage_io. Triggering the panic requires local low-privileged access, a Btrfs filesystem using the deprecated free-space cache, and a write error; no data disclosure or modification is reported.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reachable assertion in affected Linux kernel releases allows local users to crash the kernel after a Btrfs free-space-cache write fails. The first failed write drops the special free-space inode's extent map; a retry searches the commit root, receives EXTENT_MAP_HOLE, and reaches an assertion in __extent_writepage_io. Triggering the panic requires local low-privileged access, a Btrfs filesystem using the deprecated free-space cache, and a write error; no data disclosure or modification is reported.

The record

CVE
CVE-2024-26726
Published
Apr 3, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-617, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2024CVE publishedPublication date reported by the CVE source.
  2. May 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=3.12
  2. Affected versionversion=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <02f2b95b00bf57d20320ee168b30fb7f3db8e555
  3. Affected versionversion=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <143842584c1237ebc248b2547c29d16bbe400a92
  4. Affected versionversion=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <5571e41ec6e56e35f34ae9f5b3a335ef510e0ade
  5. Affected versionversion=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <7bddf18f474f166c19f91b2baf67bf7c5eda03f7
  6. Affected versionversion=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <a4b7741c8302e28073bfc6dd1c2e73598e5e535e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.12; version=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <02f2b95b00bf57d20320ee168b30fb7f3db8e555; version=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <143842584c1237ebc248b2547c29d16bbe400a92; version=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <5571e41ec6e56e35f34ae9f5b3a335ef510e0ade; version=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <7bddf18f474f166c19f91b2baf67bf7c5eda03f7; version=77cef2ec5484564eca6bd12a2b4a1e88fd766fbc <a4b7741c8302e28073bfc6dd1c2e73598e5e535e

Published CVSS scores

5.5UbuntuCVSS: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-617Reachable Assertion
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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