CVE-2026-73673

What it is

Netis NC63 router firmware V3.0.0.3327 contains an unauthenticated firmware update vulnerability that allows unauthenticated attackers to submit unsigned firmware images by exploiting a missing authentication enforcement flaw in the Boa web server and netis.cgi CGI dispatcher. Attackers can send a multipart POST request to /cgi-bin/upload_fw.cgi without a valid session cookie, bypassing authentication because Boa grants access to any path containing '.cgi' regardless of cookie validation, and netis.cgi reads but does not enforce the authentication state before invoking the firmware update handler, which accepts images validated only by a forgeable additive checksum and static product strings rather than a cryptographic signature, potentially enabling persistent router compromise.

At a glance

Exploitability

Can be exploited from the same network segment without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.5% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-08-14 13:19 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-24 15:10 UTC Last updatedMost recent change to the record

Details

Published

2026-08-14 13:19 UTC

Last modified

2026-10-24 15:10 UTC

Exploit probability

0.5% · EPSS, next 30 days

Weakness

CWE-306 · Missing authentication

Record status

Deferred

Attack profile CVSS 4.0 · 8.7

Attack vector

Adjacent network

Complexity

Low

Attack requirements

None

Privileges needed

None

User interaction

None

Confidentiality

High

Integrity

High

Availability

High