How do I check whether I am affected by CVE-2026-40615?

Open the router admin page, go to system status and read the firmware version. Firmware TOTOLINK-X2000R-Gh-V1.0.0-B20250421.1327 is confirmed vulnerable. Other builds are untested. Also check whether the admin interface is reachable from WAN, for example by testing the router's public IP on its web admin port from outside your network.

What is the fix for CVE-2026-40615?

No fixed firmware as of 2026-10-20. Check the TOTOLINK X2000R download page for a build newer than B20250421.1327. Until one exists: turn off remote/WAN administration, restrict admin access to a trusted LAN, change the default admin password, and replace the router if it cannot be isolated.

Who is not affected by CVE-2026-40615?

Not affected if: auth-required, other-firmware-version, parent-control-unused, wan-admin-disabled.

Live › vulnerability › CVE-2026-40615

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critical9.1Infrastructure

TOTOLINK X2000R router: crafted request overflows stack and runs code

Stack buffer overflow in the TOTOLINK X2000R web admin (boa). A logged-in user can POST an oversized deviceName to /boafrm/formParentControl (with modPCRule or addPCUrl set) and run code on the router. Found by Cisco Talos. Admin login is required (CVSS PR:H), but the flaw can be reached over the network. No vendor fix has been published.

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 arbitrary code on the router after logging in.
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-2026-40615

Go to dashboard

critical9.1Infrastructure

TOTOLINK X2000R router: crafted request overflows stack and runs 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 arbitrary code on the router after logging in.
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: crafted request overflows stack and runs code

Why it is critical, and not just CVSS

Who is affected

Know the next one before it finds you.

TOTOLINK X2000R router: crafted request overflows stack and runs 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