Critical Buffer Overflow Flaw Found in Totolink X2000R Router Firmware
A stack-based buffer overflow in the X2000R allows authenticated attackers to execute arbitrary code, earning a critical CVSS score of 9.1.
Key points
- CVE-2026-28763 is rated Critical with a CVSS score of 9.1.
- The flaw exists in the boa formMapDelDevice hostname functionality.
- Exploitation requires an authenticated HTTP request from an attacker.
A critical security vulnerability has been identified in specific firmware for the Totolink X2000R router. The flaw, tracked as CVE-2026-28763, allows attackers to execute arbitrary code on the device through a stack-based buffer overflow.
At a glance
- CVE
- CVE-2026-28763
- Product
- Totolink
- CVSS
- 9.1 Critical
- Weakness
- stack-based buffer overflow
- Exploited
- No known exploitation
The vulnerability resides within the boa formMapDelDevice hostname functionality. According to the National Vulnerability Database record, a specially crafted HTTP request can trigger this issue. Successful exploitation leads to arbitrary code execution, granting the attacker significant control over the compromised network hardware.
Technical Details of the Flaw
The Common Vulnerability Scoring System assigns this issue a score of 9.1, categorizing it as Critical. This high severity rating reflects the potential impact of remote code execution on network infrastructure. The weakness is classified under CWE-121, which denotes a stack-based buffer overflow condition in software.
Attackers must possess valid credentials to exploit this vulnerability. The source material specifies that an attacker can make an authenticated HTTP request to trigger the flaw. This means unauthorized users without login access cannot directly exploit this specific vector, though credential theft remains a risk.
Affected Products and Versions
The vulnerability affects the Totolink X2000R device specifically running version TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. This is the only version listed in the available source material. Users running this exact build are exposed to the risk described in the NVD record.
No other Totolink models or firmware versions are listed in the available source material. The impact is limited to devices confirmed to be running this specific software iteration. Administrators should verify their current firmware version to determine if their hardware is within the affected scope.
What should you do?
Security professionals should audit their network inventory for devices running the vulnerable firmware version. Since authentication is required for exploitation, organizations must review their access controls and password policies for router administration interfaces.
Background: Router firmware vulnerabilities
Small businesses face exposure because default router firmware rarely updates automatically. Protect your network by isolating devices, enforcing strict access controls, and verifying that your IT provider manages firmware lifecycle rather than just initial configuration.
Read the full guide: Router Firmware Vulnerabilities: Risks and Protection for Small Businesses
What to do and how to stay safe: Totolink
- Verify the firmware version on all Totolink X2000R devices to check for the vulnerable build.
- Change default administrative passwords to strong, unique credentials to mitigate authentication risks.
- Monitor network traffic for unusual HTTP requests to the router's management interface.
- Wait for the vendor to release an official patch before attempting unofficial modifications.
Step-by-step guide: Risk-Based Vulnerability Management: Prioritize Fixes by Actual Danger
General security guidance from the Threat Times newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
What is the CVSS score for CVE-2026-28763?
The vulnerability has a CVSS score of 9.1, which is rated as Critical.
Does exploiting this flaw require user authentication?
Yes, an attacker must make an authenticated HTTP request to trigger the vulnerability.
Which specific firmware version is affected?
The version TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 is affected by this stack-based buffer overflow.
