How do I check whether I am affected by CVE-2026-9659?

Log in to the router admin UI and read the firmware version. Build TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 is confirmed vulnerable; other builds are untested (unknown). Confirm the admin web interface is not reachable from the WAN side.

What is the fix for CVE-2026-9659?

No fixed firmware published as of 2026-10-23 (unknown). Mitigate: set a long unique admin password, disable remote/WAN administration, restrict admin UI to management hosts. Install a patched build only from totolink.net once released. If compromise is suspected, reflash from an official image or replace the unit and rotate Wi-Fi/VPN/PPPoE secrets.

Who is not affected by CVE-2026-9659?

Not affected if: auth-required, no-admin-web-interface-exposed, no-wan-admin, other-firmware-version, other-firmware-versions.

Live › vulnerability › CVE-2026-9659

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critical9.1Infrastructure

TOTOLINK X2000R router: stack overflow in formFilter lets attacker run code

Authenticated stack buffer overflows in the boa web server's formFilter handler (vpnUser parameter) on TOTOLINK X2000R firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. A logged-in admin sending a crafted HTTP request can run code on the router. CVSS 9.1. Part of a batch of ~30 Talos CVEs against this one build. No fix published, no known exploitation or PoC.

Summary written from the sources below. Check the originals before acting.

CVSS 3.x

9.1

critical

scored by [email protected]

known so far5 of 6

missing: exploitation

First public: Oct 20, 2026 UTC
Last modified: Oct 23, 2026
Status: open
Known exploitation: None reported
Public exploit: None on GitHub
EPSS: not scored

First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.

Why it is critical, and not just CVSS

Likelihood → · Impact ↓

critical

high

medium

high

medium

low

medium

low

Exploited: No reports yet.
Needs login: Yes.
Needs a special setup: Not known from the sources.
Reachable from: network.
Worst case: Attacker runs code on the router and takes over the network edge.
CVSS said: 9.1. The facts above say medium; we keep the sources' critical until an analyst looks.

Who is affected

1 product

Know the next one before it finds you.

Add to Slack

Live › vulnerability › CVE-2026-9659

Go to dashboard

critical9.1Infrastructure

TOTOLINK X2000R router: stack overflow in formFilter lets attacker run code

Summary written from the sources below. Check the originals before acting.

CVSS 3.x

9.1

critical

scored by [email protected]

known so far5 of 6

missing: exploitation

First public: Oct 20, 2026 UTC
Last modified: Oct 23, 2026
Status: open
Known exploitation: None reported
Public exploit: None on GitHub
EPSS: not scored

First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.

Why it is critical, and not just CVSS

Likelihood → · Impact ↓

critical

high

medium

high

medium

low

medium

low

Exploited: No reports yet.
Needs login: Yes.
Needs a special setup: Not known from the sources.
Reachable from: network.
Worst case: Attacker runs code on the router and takes over the network edge.
CVSS said: 9.1. The facts above say medium; we keep the sources' critical until an analyst looks.

Who is affected

1 product

Know the next one before it finds you.

Add to Slack

TOTOLINK X2000R router: stack overflow in formFilter lets attacker run code

Why it is critical, and not just CVSS

Who is affected

Know the next one before it finds you.

TOTOLINK X2000R router: stack overflow in formFilter lets attacker run code

Why it is critical, and not just CVSS

Who is affected

Know the next one before it finds you.

How to check

The fix

Who had it, and when

What the sources say, verbatim

Sources