PHP2Shell: Read our blog on the critical RCE vulnerabilities affecting 70% of the Internet
Wiz
Vulnerability DatabaseCVE-2025-22039

CVE-2025-22039: 
Linux Kernel vulnerability analysis and mitigation

Overview

A vulnerability in the Linux kernel's ksmbd module was discovered and assigned CVE-2025-22039. The issue was disclosed on April 16, 2025, affecting the dacloffset field handling in the Linux kernel's SMB server implementation (NVD, Ubuntu Security).

Technical details

The vulnerability stems from the dacloffset field being originally typed as int and used in an unchecked addition, which could overflow and bypass the existing bounds check in both smb_check_perm_dacl() and smb_inherit_dacl() functions. The issue was resolved by converting dacloffset to unsigned int and implementing check_add_overflow() to validate access to the DACL (NVD).

Impact

This vulnerability could result in out-of-bounds memory access and a kernel crash when dereferencing the DACL pointer, potentially leading to system instability or denial of service (NVD).

Mitigation and workarounds

The vulnerability has been patched in Linux kernel version 6.12.25-1 for Debian systems. Various Linux distributions including Ubuntu, Red Hat, and Debian are working on releasing updated kernel packages to address this vulnerability (Debian Tracker, Ubuntu Security).

Additional resources

Linux Distribution fix status

Fix availability across major Linux distributions and their releases.

Debian

Fixed

bookworm

linux: 6.1.190-1

Fixed

sid

linux: 6.12.25-1

Fixed

trixie

linux: 6.12.25-1

Fixed

Ubuntu

Fixed

bionic

linux

Not Affected

bionic (esm-infra)

linux

Not Affected

bionic (fips-updates)

linux-fips

Not Affected

bionic (fips)

linux-fips

Not Affected

devel

linux

Not Affected

focal

linux

Not Affected

focal (esm-infra)

linux-hwe-5.15: 5.15.0-202.212~20.04.1

Affected

focal (fips-updates)

linux-fips

Not Affected

RHEL / CentOS

Affected

RHEL 8

Not Affected

RHEL 9

Not Affected

RHEL 10

Not Affected

Source: This report was generated using AI

Related Linux Kernel vulnerabilities:

CVE ID

Severity

Score

Technologies

Component name

CISA KEV exploit

Has fix

Published date

CVE-2026-98862MEDIUM6
  • Linux Kernel logoLinux Kernel
  • linux-iot
NoYesOct 18, 2026
CVE-2026-98859MEDIUM5.7
  • Linux Kernel logoLinux Kernel
  • kernel-64k-modules-partner
NoYesOct 18, 2026
CVE-2026-98861MEDIUM4.7
  • Linux Kernel logoLinux Kernel
  • linux-fips
NoYesOct 18, 2026
CVE-2026-98863NONEN/A
  • Linux Kernel logoLinux Kernel
  • linux-riscv
NoYesOct 18, 2026
CVE-2026-98858NONEN/A
  • Linux Kernel logoLinux Kernel
  • linux-ibm-5.15
NoYesOct 18, 2026

Free Vulnerability Assessment

Benchmark your Cloud Security Posture

Evaluate your cloud security practices across 9 security domains to benchmark your risk level and identify gaps in your defenses.

Request assessment

Additional Wiz resources

Cloud Vulnerability DB

Cloud Vulnerability DB

A community-led vulnerabilities database

Cloud Threat Landscape

Cloud Threat Landscape

A threat intelligence database

PEACH

PEACH

A tenant isolation framework

Get a personalized demo

Ready to see Wiz in action?

"Best User Experience I have ever seen, provides full visibility to cloud workloads."
David EstlickCISO
"Wiz provides a single pane of glass to see what is going on in our cloud environments."
Adam FletcherChief Security Officer
"We know that if Wiz identifies something as critical, it actually is."
Greg PoniatowskiHead of Threat and Vulnerability Management
Get a demo