CVE-2026-43361Public exploit

Filesystem write interruption via received-subvolume UUID overflow

Published May 8, 2026 · Updated May 8, 2026

Denial of service in Linux Kernel allows local users to force a Btrfs filesystem into read-only mode via repeated received-subvolume snapshots. During snapshot creation, create_pending_snapshot treats -EOVERFLOW from btrfs_uuid_tree_add for a BTRFS_UUID_KEY_RECEIVED_SUBVOL item as fatal and aborts the transaction. Ownership of the received subvolume is sufficient because the path requires inode_owner_or_capable() rather than CAP_SYS_ADMIN; the abort interrupts writes across the mounted filesystem.

CVSS severity5.5
Medium
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

Denial of service in Linux Kernel allows local users to force a Btrfs filesystem into read-only mode via repeated received-subvolume snapshots. During snapshot creation, create_pending_snapshot treats -EOVERFLOW from btrfs_uuid_tree_add for a BTRFS_UUID_KEY_RECEIVED_SUBVOL item as fatal and aborts the transaction. Ownership of the received subvolume is sufficient because the path requires inode_owner_or_capable() rather than CAP_SYS_ADMIN; the abort interrupts writes across the mounted filesystem.

The record

CVE
CVE-2026-43361
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <6bce705b699cba9afccb996c77d194fe003dfa2a
  3. Affected versionversion=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <770af8e465c2c3de528f85e840eab462dd41542b
  4. Affected versionversion=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <9a9227b488ffb7cdbb5d930a01fc6956c05ba61a
  5. Affected versionversion=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <bac55dde8efa457e769c934fd88a63f2141ba238
  6. Affected versionversion=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <e1b18b959025e6b5dbad668f391f65d34b39595a
  7. Affected versionversion=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <e3d8efc157bc590457d3e31da403af1a221643d6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.12; version=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <6bce705b699cba9afccb996c77d194fe003dfa2a; version=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <770af8e465c2c3de528f85e840eab462dd41542b; version=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <9a9227b488ffb7cdbb5d930a01fc6956c05ba61a; version=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <bac55dde8efa457e769c934fd88a63f2141ba238; version=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <e1b18b959025e6b5dbad668f391f65d34b39595a; version=dd5f9615fc5c5e8d3751aab3a17b92768fb1ce70 <e3d8efc157bc590457d3e31da403af1a221643d6

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

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

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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