CVE-2026-43365Network attack vector

Filesystem unavailability via undersized XFS log rounding

Published May 8, 2026 · Updated May 8, 2026

Improper log rounding in Linux Kernel XFS allows attackers to corrupt logs and leave affected filesystems unmountable. When the superblock omits a log stripe unit, xfs_log.c sets l_iclog_roundoff to 512 instead of the 4 KiB physical sector size, producing torn log writes. Reachability requires a crafted on-disk XFS superblock and 4 KiB physical sectors; the resulting CRC failures can prevent log recovery and mounting.

CVSS severity8.2
High
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper log rounding in Linux Kernel XFS allows attackers to corrupt logs and leave affected filesystems unmountable. When the superblock omits a log stripe unit, xfs_log.c sets l_iclog_roundoff to 512 instead of the 4 KiB physical sector size, producing torn log writes. Reachability requires a crafted on-disk XFS superblock and 4 KiB physical sectors; the resulting CRC failures can prevent log recovery and mounting.

The record

CVE
CVE-2026-43365
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1565.001
Attack vector
network
Privileges
unauthenticated

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=5.14
  2. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <2ecda4b83749c1fef0c9dea4fd5e8b513aba3e40
  3. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <41e91dff2d3974730b5ee50daa8e27ec254cbf91
  4. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <446a1f5bb64ba38adb93cb043ff0f7b85e8937ca
  5. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <52a8a1ba883defbfe3200baa22cf4cd21985d51a
  6. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <5afae524f83d6a18517298491a5624cb0eae5029
  7. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <5e7148402dfc4a5b7894d8e97b15e5c2e70924aa
  8. Affected versionversion=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <e88ce9f0536f3b2149afb70625cfc4bd74a4ac6d

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.14; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <2ecda4b83749c1fef0c9dea4fd5e8b513aba3e40; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <41e91dff2d3974730b5ee50daa8e27ec254cbf91; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <446a1f5bb64ba38adb93cb043ff0f7b85e8937ca; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <52a8a1ba883defbfe3200baa22cf4cd21985d51a; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <5afae524f83d6a18517298491a5624cb0eae5029; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <5e7148402dfc4a5b7894d8e97b15e5c2e70924aa; version=a6a65fef5ef8d0a6a0ce514eb66b2f3dfa777b48 <e88ce9f0536f3b2149afb70625cfc4bd74a4ac6d

Published CVSS scores

7.1UbuntuCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
8.2kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
5.5Oracle LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.2UbuntuCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1565.001Stored Data Manipulation

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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