CVE-2026-73673 Netis NC63 V3.0.0.3327 Unauthenticated Firmware Update with Missing Cryptographic Firmware Authentication
Unauthenticated attackers can upload unsigned firmware to Netis NC63 routers, enabling persistent compromise and full control of the device.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-73673?
CVE-2026-73673 is a high-severity missing authorization vulnerability in Netis NC63 Wireless AC1200 Router, published on 14 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
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.
Weakness: CWE-306
Which versions are affected by CVE-2026-73673?
How do I fix CVE-2026-73673?
No fix has been published for CVE-2026-73673 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-73673 being exploited?
There is no known exploitation of CVE-2026-73673 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-mqjf-hpmj-9gr8.