CVE-2026-43228

Kernel crash via corrupted HFS count metadata

Published May 6, 2026 · Updated May 6, 2026

Reachable assertion in Linux Kernel HFS 6.18 through 6.19.5 allows local users to crash the kernel via a corrupted HFS volume. The HFS driver accepts invalid next_id, folder_count, or file_count values from the master directory block, then reaches BUG_ON checks when those 64-bit counters exceed U32_MAX. Triggering requires local access that causes the kernel to process malformed HFS metadata; the documented consequence is a kernel crash, with no reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.11%
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 Linux Kernel HFS 6.18 through 6.19.5 allows local users to crash the kernel via a corrupted HFS volume. The HFS driver accepts invalid next_id, folder_count, or file_count values from the master directory block, then reaches BUG_ON checks when those 64-bit counters exceed U32_MAX. Triggering requires local access that causes the kernel to process malformed HFS metadata; the documented consequence is a kernel crash, with no reported data disclosure or modification.

The record

CVE
CVE-2026-43228
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-617, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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 <b226804532a875c10276168dc55ce752944096bd
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b6536c1ced315fa645576d3a39c6e07f2a472962

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b226804532a875c10276168dc55ce752944096bd; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <b6536c1ced315fa645576d3a39c6e07f2a472962

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-617Reachable Assertion
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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