TOTOLINK X2000R: Stack-based buffer overflow in Mcli functionality
Summary
A stack-based buffer overflow in the Mcli functionality of the TOTOLINK X2000R home router allows an attacker to execute arbitrary code by sending a specially crafted HTTP request. The attacker must first be authenticated to the web administration interface. The CVSS score of 9.1 reflects the impact if an attacker has valid administrative access, and the vendor has not published a fix known to the sources.
Affected
- TOTOLINK X2000R, firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 (Talos-confirmed; other versions not confirmed)
Fixed in
Unknown.
Workaround
- No vendor mitigation guidance found.
- Remove the web administration interface from WAN access and disable remote management.
- Restrict admin access to specific LAN hosts and use a unique, strong admin password.
Exploitation
- CISA SSVC: exploitation none, automatable no, technical impact total.
- Not listed in CISA KEV.
- No public proof of concept found in searches; this does not prove none exists.
- No known exploitation in the wild.
Our recommendation
- Inventory all TOTOLINK X2000R devices and check their firmware versions.
- Remove WAN access to the admin interface and disable remote management now.
- Restrict admin access to specific LAN hosts and enforce strong, unique passwords.
- Monitor the vendor for a fixed firmware; if none is published, plan to replace the device.
- Rate this as medium-high for SMEs, raising it to high if the admin interface is internet-reachable.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Cisco Talos TALOS-2026-2439 talosintelligence.com
- OpenCVE CVE-2026-10139 app.opencve.io
- Strix CVE-2026-10139 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 06:10.
Original description (NVD)
A stack-based buffer overflow vulnerability exists in the Mcli functionality of X2000R (version(s): TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327). A specially crafted HTTP request can lead to arbitrary code execution. An attacker can make an authenticated HTTP request to trigger this vulnerability.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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