Zero Radar
← feed
CriticalVulnerabilityCVE-2026-42019updated 25 Oct 2026, 15:22 UTC

TOTOLINK X2000R router can be taken over through its IPv6 PPPoE setup page

A router setup page does not check the length of one input field, so a logged-in user can send oversized data and run their own code on the router. Anyone who controls the router could then spy on traffic or change its settings.

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. 1Authenticated attackerNeeds a valid login to the router
  2. 2Crafted HTTP requestOversized pppoe_dns1 value sent
  3. 3Stack buffer overflowformIpv6Setup overflows its stack buffer
  4. 4Code executionAttacker code runs on the router
  5. ResultAttacker controls the router

What happened

Multiple stack-based buffer overflows exist in the boa formIpv6Setup PPPoE functionality of TOTOLINK X2000R firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327, triggered via the pppoe_dns1 parameter in an authenticated HTTP request, leading to arbitrary code execution.

Why it is dangerous: Successful exploitation gives full control of the router, exposing all traffic on the network and enabling further attacks on connected devices.

Are you affected?

You are affected if you run TOTOLINK X2000R router firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 with the web management interface reachable by an attacker.

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

What to do

  1. Check whether your TOTOLINK X2000R runs firmware B20250421.1327 and look for a newer firmware from TOTOLINK.
  2. Install the newer firmware if one is available; no fixed version is stated in the sources.
  3. Restrict access to the router's web admin page to trusted devices and do not expose it to the internet.
  4. Change the router's admin password to a strong, unique one.

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-2026-42019 · GHSA-6934-8h2c-7627
CVSS
9.1 / 10
EPSS
0.7% 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 its IPv6 PPPoE setup page · Zero Radar