Zero Radar
← feed
CriticalVulnerabilityCVE-2026-9659updated 25 Oct 2026, 15:22 UTC

TOTOLINK X2000R router can be taken over through a crafted web request

A specially crafted request sent to the router's web settings page can overflow memory and let an attacker run their own code on the device. Someone who can log in to the router's admin page can do this.

Official, 2 sources
SeverityCriticalCVSS 9.1 of 10
Being exploited?UnclearNo reports either way yet
Fix available?UnclearNo fixed version published in the sources yet
How sure is this?Official, 2 sourcesBacked by an official source

How the attack works simplified

  1. 1Attacker with loginNeeds valid admin credentials to the router
  2. 2Crafted HTTP requestSends oversized vpnUser value to formFilter
  3. 3Stack buffer overflowBoa web server memory is overwritten
  4. 4Code executionAttacker runs their own code on router
  5. ResultAttacker controls the router

What happened

Stack-based buffer overflows in the boa web server's formFilter handler on TOTOLINK X2000R, triggered via the vpnUser parameter, allow arbitrary code execution.

Why it is dangerous: An attacker who controls the router can read or redirect traffic, reach devices on the home or office network, and persist on the device. Anyone running this firmware exposed to untrusted users or networks is at risk.

Are you affected?

You are affected if you run TOTOLINK X2000R with firmware version TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327.

TOTOLINK X2000R, firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327

What to do

  1. Check the router's firmware version in its admin page and confirm whether it matches the affected build.
  2. Restrict access to the router's web admin interface so only trusted devices can reach it.
  3. Change default admin passwords and watch for unexpected configuration changes.
  4. Check the vendor's TOTOLINK support site for a fixed firmware release and install it when available.

Timeline

  1. 20 Oct 2026, 21:17 UTC
    Publicly disclosed
  2. 20 Oct 2026, 21:17 UTC
    Reported by NVD · NVD
  3. 25 Oct 2026, 15:22 UTC
    GitHub Advisory reported on it · GitHub Advisory

Sources 2 reports, oldest first

Official vendor, government CERT or advisory database

Technical details

ID
CVE-2026-9659 · GHSA-7crj-p2x6-x2g5
CVSS
9.1 / 10
EPSS
0.8% chance of exploitation within 30 days
Disclosed
20 Oct 2026, 21:17 UTC
On Zero Radar
before the radar started
Last change
25 Oct 2026, 15:22 UTC

The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works

TOTOLINK X2000R router can be taken over through a crafted web request · Zero Radar