Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-51705 – Unauthenticated Access Control Bypass (RCE-adjacent Config Tampering) – TOTOLINK T6

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-51705 is a critical improper access control vulnerability affecting the TOTOLINK T6 wireless router running firmware version 4.1.5cu.748_B20211015. The flaw resides in the setWiFiMeshName function exposed via the device’s /cgi-bin/cstecgi.cgi endpoint, and allows a completely unauthenticated, remote attacker to rename mesh network entries on the device. The vulnerability carries a CVSS v3.1 base score of 9.8 (Critical), reflecting its network attack vector, low complexity, and lack of any authentication or user interaction requirement.

Technical details

  • Root cause: The setWiFiMeshName function within the cstecgi.cgi CGI handler fails to enforce proper access control/authentication checks before processing requests that modify mesh network naming configuration.
  • Trigger conditions: An attacker sends a specially crafted HTTP POST request to /cgi-bin/cstecgi.cgi targeting the setWiFiMeshName action; no valid session, credentials, or prior authentication is required.
  • Attack vector: Remote, over the network (AV:N) — the affected CGI endpoint is typically reachable via the device’s management interface, and in cases where remote administration or the interface is exposed to the internet, this is exploitable without any local network access.
  • Impact: Successful exploitation allows unauthenticated attackers to rename mesh network entries, which can be leveraged to manipulate mesh topology/configuration, potentially disrupt legitimate mesh operation, facilitate further social-engineering or man-in-the-middle setups, or serve as a foothold/indicator in broader device compromise given the pattern of related access-control flaws affecting the same CGI handler.

Affected software

  • TOTOLINK T6 — firmware version 4.1.5cu.748_B20211015

Severity

  • CVSS v3.1 Base Score: 9.8 (Critical)
  • Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • CWE-284: Improper Access Control

Mitigation and recommended actions

  • Immediate: As of publication, no vendor patch or updated firmware version addressing CVE-2026-51705 has been confirmed. Check the TOTOLINK support/download portal regularly for a firmware update for the T6 model and apply it as soon as it becomes available.
  • If no patch is available:
    • Disable remote/WAN-facing administration access to the TOTOLINK T6 management interface.
    • Restrict access to /cgi-bin/cstecgi.cgi and the device’s web management UI to trusted internal network segments only, using firewall rules or network segmentation.
    • Place affected devices behind a VPN or additional authentication gateway if remote management is required.
    • Monitor device configuration (especially mesh/Wi-Fi settings) for unauthorized changes.
    • Consider replacing or isolating end-of-life/unsupported TOTOLINK devices where no patch is forthcoming, as this vulnerability is part of a broader pattern of unauthenticated access-control issues identified in the same firmware’s CGI interface.

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge