CVE-2026-20408
📋 TL;DR
This CVE describes a heap buffer overflow vulnerability in wlan (wireless LAN) components that allows remote attackers to execute arbitrary code without user interaction. It affects systems using vulnerable MediaTek wireless components, potentially leading to privilege escalation. The vulnerability can be exploited by attackers within wireless range of the target device.
💻 Affected Systems
- MediaTek wireless chipsets and devices using them
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full system control, installs persistent malware, and pivots to other network systems.
Likely Case
Attacker gains elevated privileges on the affected device, potentially accessing sensitive data or disrupting services.
If Mitigated
With proper network segmentation and monitoring, impact is limited to isolated wireless segments with minimal data exposure.
🎯 Exploit Status
No authentication required; attacker needs to be within wireless range; heap exploitation requires specific conditions
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: WCNCR00461651
Vendor Advisory: https://corp.mediatek.com/product-security-bulletin/February-2026
Restart Required: Yes
Instructions:
1. Check device manufacturer for firmware updates. 2. Apply patch WCNCR00461651. 3. Reboot device. 4. Verify patch installation.
🔧 Temporary Workarounds
Disable vulnerable wireless interfaces
linuxTemporarily disable affected wireless interfaces to prevent exploitation
sudo ifconfig wlan0 down
sudo nmcli radio wifi off
Restrict wireless network access
allImplement MAC address filtering and reduce wireless broadcast range
🧯 If You Can't Patch
- Segment wireless networks from critical infrastructure
- Implement strict network monitoring for unusual wireless traffic patterns
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against vendor advisory; examine wireless driver versionsCheck Version:
cat /proc/version or manufacturer-specific firmware check commandsVerify Fix Applied:
Verify patch WCNCR00461651 is installed via firmware version check📡 Detection & Monitoring
Log Indicators:
- Unusual wireless connection attempts
- Kernel panic or crash logs related to wlan drivers
- Memory corruption warnings
Network Indicators:
- Abnormal wireless packet patterns
- Unexpected wireless protocol violations
SIEM Query:
source="wireless_logs" AND (event_type="buffer_overflow" OR event_type="kernel_panic")