CVE-2024-26644

Filesystem denial of service via zero-reference snapshot root

Published Mar 26, 2024 · Updated May 11, 2026

Denial of service in Linux btrfs allows local users to force a mounted filesystem read-only through the snapshot ioctl. create_pending_snapshot() copies a deleted source subvolume's root item with refs set to zero, then btrfs_insert_root() inserts the invalid root and btrfs_get_new_fs_root() returns -ENOENT, aborting the transaction. A local user needs an open descriptor for a deleted btrfs subvolume and permission to request a snapshot; the result interrupts writes on the affected filesystem.

CVSS severity5.5
Medium
EPSS probability0.23%
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 btrfs allows local users to force a mounted filesystem read-only through the snapshot ioctl. create_pending_snapshot() copies a deleted source subvolume's root item with refs set to zero, then btrfs_insert_root() inserts the invalid root and btrfs_get_new_fs_root() returns -ENOENT, aborting the transaction. A local user needs an open descriptor for a deleted btrfs subvolume and permission to request a snapshot; the result interrupts writes on the affected filesystem.

The record

CVE
CVE-2024-26644
Published
Mar 26, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-908, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 26, 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=2.6.35
  2. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <0877497dc97834728e1b528ddf1e1c484292c29c
  3. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <2bdf872bcfe629a6202ffd6641615a8ed00e8464
  4. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <6e6bca99e8d88d989a7cde4c064abea552d5219b
  5. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <7081929ab2572920e94d70be3d332e5c9f97095a
  6. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <c06941564027bdbc01d2df7f41e333c11cb0482d
  7. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <d8680b722f0ff6d7a01ddacc1844e0d52354d6ff
  8. Affected versionversion=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <ec794a7528199e1be6d47bec03f4755aa75df256

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.35; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <0877497dc97834728e1b528ddf1e1c484292c29c; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <2bdf872bcfe629a6202ffd6641615a8ed00e8464; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <6e6bca99e8d88d989a7cde4c064abea552d5219b; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <7081929ab2572920e94d70be3d332e5c9f97095a; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <c06941564027bdbc01d2df7f41e333c11cb0482d; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <d8680b722f0ff6d7a01ddacc1844e0d52354d6ff; version=d68fc57b7e3245cfacf2e3b47acfed1946a11786 <ec794a7528199e1be6d47bec03f4755aa75df256

Published CVSS scores

5.5NVDCVSS: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-908Use of Uninitialized Resource
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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