How do I check whether I am affected by CVE-2026-111711?

Log in to the router admin page and read the firmware version (System/Status page); NR256CN on 1.5.140116 or earlier is affected. Check whether the web admin (Boa, /router/*.cgi) is reachable from WAN or from untrusted LAN segments, e.g. scan your public IP on the admin port (80/8080).

What is the fix for CVE-2026-111711?

No fixed firmware published as of 2026-10-23 (unknown; check Netcore support for a build newer than 1.5.140116). Mitigation: disable WAN/remote administration, restrict admin interface to a trusted management host, replace the device if it must be internet-facing.

Who is not affected by CVE-2026-111711?

Not affected if: admin-interface-not-exposed.

Live › vulnerability › CVE-2026-111711

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critical9.8Infrastructure

Netcore NR256CN through 1.5.140116 contains a pre-authentication stack overflow vulnerability in the Boa web…

Netcore NR256CN routers through firmware 1.5.140116 have a stack overflow in the Boa web server's Basic-auth check, where an overlong username is copied into a 64-byte buffer without a length limit. An unauthenticated attacker can crash the web server or potentially run code on the device.

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

CVSS 4.0

9.8

critical

scored by [email protected]

known so far5 of 6

missing: exploitation

First public: Oct 16, 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: No.
Needs a special setup: Not known from the sources.
Reachable from: network.
Worst case: Unauthenticated attacker may execute code on the router.
CVSS said: 9.8. The facts above say high; 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-2026-111711

Go to dashboard

critical9.8Infrastructure

Netcore NR256CN through 1.5.140116 contains a pre-authentication stack overflow vulnerability in the Boa web…

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

CVSS 4.0

9.8

critical

scored by [email protected]

known so far5 of 6

missing: exploitation

First public: Oct 16, 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: No.
Needs a special setup: Not known from the sources.
Reachable from: network.
Worst case: Unauthenticated attacker may execute code on the router.
CVSS said: 9.8. The facts above say high; 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

Netcore NR256CN through 1.5.140116 contains a pre-authentication stack overflow vulnerability in the Boa web…

Why it is critical, and not just CVSS

Who is affected

Know the next one before it finds you.

Netcore NR256CN through 1.5.140116 contains a pre-authentication stack overflow vulnerability in the Boa web…

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