CVE-2026-45999Public exploit

Kernel-memory disclosure and service interruption via EROFS underflow

Published May 27, 2026 · Updated May 27, 2026

Out-of-bounds read in EROFS LZ4 decompression in affected Linux Kernel releases allows local users to disclose memory or interrupt service. z_erofs_lz4_handle_overlap subtracts a larger input-page count from a smaller output-page count, wrapping the unsigned result before indexing beyond decompressed_pages. Exploitation requires a crafted EROFS image, EROFS kernel support, and user interaction to mount and read it; consequences are limited to kernel-memory exposure and availability loss.

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

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in EROFS LZ4 decompression in affected Linux Kernel releases allows local users to disclose memory or interrupt service. z_erofs_lz4_handle_overlap subtracts a larger input-page count from a smaller output-page count, wrapping the unsigned result before indexing beyond decompressed_pages. Exploitation requires a crafted EROFS image, EROFS kernel support, and user interaction to mount and read it; consequences are limited to kernel-memory exposure and availability loss.

The record

CVE
CVE-2026-45999
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-191, T1204.002
Attack vector
local
Privileges
unauthenticated

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=5.13
  2. Affected versionversion=598162d050801e556750defff4ddab499e5d76ed <21e161de2dc660b1bb70ef5b156ab8e6e1cca3ab
  3. Affected versionversion=598162d050801e556750defff4ddab499e5d76ed <43a878639b90e9721ffa5eb616a7e6d8454adef3
  4. Affected versionversion=598162d050801e556750defff4ddab499e5d76ed <bbbbb3f0d7864238a8da2a94cd6ec013fee06a2e
  5. Affected versionversion=598162d050801e556750defff4ddab499e5d76ed <c9ce18e6bb2c467ec85756dc7989b547b7584fee
  6. Affected versionversion=598162d050801e556750defff4ddab499e5d76ed <f1374fa6e57fd836623668d782ded9244cfd2938

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.13; version=598162d050801e556750defff4ddab499e5d76ed <21e161de2dc660b1bb70ef5b156ab8e6e1cca3ab; version=598162d050801e556750defff4ddab499e5d76ed <43a878639b90e9721ffa5eb616a7e6d8454adef3; version=598162d050801e556750defff4ddab499e5d76ed <bbbbb3f0d7864238a8da2a94cd6ec013fee06a2e; version=598162d050801e556750defff4ddab499e5d76ed <c9ce18e6bb2c467ec85756dc7989b547b7584fee; version=598162d050801e556750defff4ddab499e5d76ed <f1374fa6e57fd836623668d782ded9244cfd2938

Published CVSS scores

7.1kernel.orgCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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.

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo