How do I check whether I am affected by CVE-2026-9817?

In the router admin UI (System / firmware info) read the firmware version. Vulnerable if it is TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327. Also check whether the admin interface is reachable from WAN or untrusted LAN/Wi-Fi.

What is the fix for CVE-2026-9817?

No fixed firmware known. Check totolink.net X2000R downloads (https://www.totolink.net/home/menu/newstpl/menu_newstpl/products/id/242.html) for a build newer than B20250421.1327. Until then: disable remote/WAN admin, restrict the admin UI to a trusted LAN, change the default admin password, and replace the device if it must be exposed.

Who is not affected by CVE-2026-9817?

Not affected if: auth-required, no-web-admin-exposure, other-firmware-version, wan-admin-disabled.

Live › vulnerability › CVE-2026-9817

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critical9.1Infrastructure

TOTOLINK X2000R router: upload handler overflow lets authenticated attacker run code

Stack overflow in the boa web server's /boafrm/formUploadFile on TOTOLINK X2000R: the multipart filename is copied with sprintf into a 0xc8-byte stack buffer with no length check. An attacker logged in to the admin interface can send a crafted upload and get code execution as the boa process (crash shows control of the return address). CVSS 9.1 (PR:H). Found by Cisco Talos; vendor acknowledged but no patched firmware is published as far as sources show.

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 with full device control.
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-2026-9817

Go to dashboard

critical9.1Infrastructure

TOTOLINK X2000R router: upload handler overflow lets authenticated 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 with full device control.
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: upload handler overflow lets authenticated 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: upload handler overflow lets authenticated 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