Vulnerability · Published Aug 14, 2026 · Assigned by VulnCheck
CVE-2026-73673Netis NC63 V3.0.0.3327 Unauthenticated Firmware Update with Missing Cryptographic Firmware Authentication
High 8.8
In plain English
A high-severity missing authentication in Netis NC63 Wireless AC1200 Router from Netis Systems Co., Ltd.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code.
Official description
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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Netis Systems Co., Ltd. | Netis NC63 Wireless AC1200 Router | 0 – through V3.0.0.3327 |
Weakness: CWE-306 · Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- Netis NC63 Product Page (Vendor) issue-tracking
- Blog Post technical-description
- GitHub Repository technical-description
- https://www.vulncheck.com/advisories/netis-nc63-unauthenticated-firmware-update-with-missing-cryptographic-firmware-authentication third-party-advisory
- Netis support/download page product