CVE-2024-26936 – This CVE describes a buffer overflow vulnerabil... (How to Fix)

Q: What is the severity of CVE-2024-26936?

CVE-2024-26936 has a CVSS score of 7.8 (HIGH). This CVE describes a buffer overflow vulnerability in the Linux kernel's ksmbd SMB server module. Attackers could exploit this by sending specially crafted SMB requests to trigger out-of-bounds memory access, potentially leading to system crashes or arbitrary code execution. Systems running vulnerable Linux kernel versions with ksmbd enabled are affected.

📋 TL;DR

This CVE describes a buffer overflow vulnerability in the Linux kernel's ksmbd SMB server module. Attackers could exploit this by sending specially crafted SMB requests to trigger out-of-bounds memory access, potentially leading to system crashes or arbitrary code execution. Systems running vulnerable Linux kernel versions with ksmbd enabled are affected.

💻 Affected Systems

Products:

Linux kernel

Versions: Specific kernel versions with vulnerable ksmbd commits (check git references)

Operating Systems: Linux distributions using affected kernel versions

Default Config Vulnerable: ✅ No

Notes: Only vulnerable if ksmbd module is loaded and SMB server is enabled

📦 What is this software?

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

Linux Kernel by Linux

The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...

Learn more about Linux Kernel →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution with kernel privileges leading to complete system compromise

🟠

Likely Case

Kernel panic causing system crash and denial of service

🟢

If Mitigated

Limited impact if ksmbd is disabled or proper network segmentation is in place

🌐 Internet-Facing: MEDIUM - Requires ksmbd service to be exposed and accessible

🏢 Internal Only: MEDIUM - Internal attackers could exploit if ksmbd is enabled

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires sending malformed SMB packets to ksmbd service

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Kernel versions with fixes from provided git commits

Vendor Advisory: https://git.kernel.org/stable/c/17cf0c2794bdb6f39671265aa18aea5c22ee8c4a

Restart Required: Yes

Instructions:

1. Update Linux kernel to patched version 2. Reboot system 3. Verify ksmbd module loads correctly

🔧 Temporary Workarounds

Disable ksmbd module

linux

Prevent loading of vulnerable ksmbd kernel module

echo 'blacklist ksmbd' >> /etc/modprobe.d/blacklist-ksmbd.conf
rmmod ksmbd

Block SMB ports

linux

Block SMB network access

iptables -A INPUT -p tcp --dport 445 -j DROP
iptables -A INPUT -p tcp --dport 139 -j DROP

🧯 If You Can't Patch

Disable ksmbd service if not required
Implement strict network segmentation and firewall rules to limit SMB access

🔍 How to Verify

Check if Vulnerable:

Check if ksmbd module is loaded: lsmod | grep ksmbd

Check Version:

uname -r

Verify Fix Applied:

Verify kernel version is patched and ksmbd module version matches fixed commits

📡 Detection & Monitoring

Log Indicators:

Kernel panic logs
ksmbd crash dumps
unusual SMB request patterns

Network Indicators:

Malformed SMB packets to port 445/139
unusual SMB protocol violations

SIEM Query:

source="kernel" AND "panic" OR "ksmbd" AND ("crash" OR "oops")

📊 Metadata

CVE ID: CVE-2024-26936

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-120

Published: May 1, 2024

Last Updated: September 18, 2025

🔗 References

📤 Share & Export

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🔗 Related Vulnerabilities

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