CVE-2025-8826
📋 TL;DR
A stack-based buffer overflow vulnerability in Linksys WiFi range extenders allows remote attackers to execute arbitrary code by manipulating authentication mode parameters. This affects multiple RE series models up to August 2025 firmware. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Linksys RE6250
- Linksys RE6300
- Linksys RE6350
- Linksys RE6500
- Linksys RE7000
- Linksys RE9000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, creation of persistent backdoor, lateral movement to internal networks, and botnet recruitment.
Likely Case
Device takeover enabling network traffic interception, credential theft, and use as pivot point for further attacks.
If Mitigated
Denial of service or device crash if exploit fails or protections limit code execution.
🎯 Exploit Status
Proof-of-concept exploit code is publicly available on GitHub. The vulnerability requires no authentication and has simple exploitation steps.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Check Linksys support website for firmware updates. 2. If update available, download and install via web interface. 3. Reboot device after update. 4. Verify firmware version is newer than 20250801.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to web management interface
Access web interface > Administration > Remote Management > Disable
Network Segmentation
allIsolate range extenders on separate VLAN
Configure firewall rules to restrict access to device management ports (typically 80, 443)
🧯 If You Can't Patch
- Replace affected devices with patched models or different vendors
- Implement strict network access controls and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check firmware version in web interface: Login > Administration > Firmware Upgrade. If version date is 20250801 or earlier, device is vulnerable.Check Version:
curl -s http://device-ip/status.cgi | grep firmware or check web interface manuallyVerify Fix Applied:
Verify firmware version shows date after 20250801. Test by attempting to access /goform/RP_setBasicAuto with malformed parameters (in safe environment).📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to /goform/RP_setBasicAuto
- Device crash/reboot logs
- Unusual process execution
Network Indicators:
- HTTP POST to /goform/RP_setBasicAuto with long apcli_AuthMode parameters
- Unexpected outbound connections from range extender
SIEM Query:
source="linksys-extender" AND (url="/goform/RP_setBasicAuto" OR (process="crash" AND device_type="RE6*" OR device_type="RE7*" OR device_type="RE9*"))