TOTOLINK X2000R: Stack-based buffer overflow in IPv6 static DNS configuration
Summary
The TOTOLINK X2000R router firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 contains stack-based buffer overflows in the boa web management function formIpv6Setup (static network configuration), triggered through the static_dns2 parameter. An attacker who holds valid credentials can send a specially crafted HTTP request to execute arbitrary code on the device. Exploitation requires authentication, and the CVSS score is 9.1 (critical).
Affected
- TOTOLINK X2000R, firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 (the only version listed in the CVE record)
- Other versions: Unknown.
Fixed in
Unknown. No vendor fix or firmware release has been confirmed.
Workaround
- No workaround is documented for this CVE. Treat the device as unpatched until TOTOLINK confirms a fix.
- Block access to the router's management interface from the internet and restrict which internal systems can reach it.
- Isolate router management traffic on a separate network segment.
- Change the default administrator password and disable remote management if it is enabled.
Exploitation
- No evidence of exploitation in the wild; the CVE is not listed in CISA KEV.
- CISA SSVC assessment in the CVE record: Exploitation none, Automatable no.
- No public proof of concept found at the time of research.
Our recommendation
- Check whether any TOTOLINK X2000R devices are in use, including their firmware version and internet exposure.
- Restrict administrative access to trusted internal hosts and disable WAN-side management.
- Replace default or weak passwords and review administrator accounts.
- Apply the vendor firmware update as soon as TOTOLINK releases one, and monitor the vendor support site and the CVE for updates.
- Verify the affected function against the Cisco Talos report, as its index entry refers to a different function.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Cisco Talos TALOS-2026-2395 talosintelligence.com
- OpenCVE CVE-2026-42022 app.opencve.io
- Strix CVE-2026-42022 www.strix.ai
- ThreatInt CVE-2026-42022 cve.threatint.com
- VulDB 424069 vuldb.com
- Vulners Talos TALOS-2026-2395 vulners.com
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, 05:57.
Original description (NVD)
Multiple stack-based buffer overflow vulnerabilities exist in the boa formIpv6Setup static network configuration functionality of Totolink X2000R 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 these vulnerabilities. This vulnerability concerns the static_dns2 parameter.
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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