CVE-2026-45943

Kernel crash via invalid EROFS compressed folio

Published May 27, 2026 · Updated May 27, 2026

NULL pointer dereference in the Linux Kernel EROFS subsystem allows local users to crash the kernel during compressed file reads. The z_erofs_decompress_pcluster() path assumes a compressed folio is valid after its pcluster enters an I/O chain even when reading the inline data failed. Triggering the crash requires an EROFS ztailpacking pcluster and a fatal signal while read_mapping_folio() is reading inline data.

CVSS severity7.1
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux Kernel EROFS subsystem allows local users to crash the kernel during compressed file reads. The z_erofs_decompress_pcluster() path assumes a compressed folio is valid after its pcluster enters an I/O chain even when reading the inline data failed. Triggering the crash requires an EROFS ztailpacking pcluster and a fatal signal while read_mapping_folio() is reading inline data.

The record

CVE
CVE-2026-45943
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 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=5.17
  2. Affected versionversion=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <5de1aa0bf3a5db0b3cbf61959da5ac61250833ed
  3. Affected versionversion=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <92088bd9aa2a7246bba8b9648fbc64edd173cf17
  4. Affected versionversion=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <ad07ea069f924465061cfee40ef2861bb99f4dd8
  5. Affected versionversion=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <c134a40f86efb8d6b5a949ef70e06d5752209be5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.17; version=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <5de1aa0bf3a5db0b3cbf61959da5ac61250833ed; version=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <92088bd9aa2a7246bba8b9648fbc64edd173cf17; version=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <ad07ea069f924465061cfee40ef2861bb99f4dd8; version=cecf864d3d76d50e3d9c58145e286a0b8c284e92 <c134a40f86efb8d6b5a949ef70e06d5752209be5

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/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-125Out-of-bounds Read
T1499.004Endpoint Denial of Service: Application 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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