CVE-2026-76070 Netis NC63 V3.0.0.3327 Stack Buffer Overflow via Login Password Parameter
Unauthenticated attackers can achieve remote code execution with root privileges via a stack buffer overflow in the login handler.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-76070?
CVE-2026-76070 is a critical memory corruption vulnerability in Netis Systems NC63, published on 24 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Netis NC63 firmware through V3.0.0.3327 contains a stack-based buffer overflow vulnerability that allows unauthenticated remote attackers to overwrite saved stack state by submitting an oversized Base64-encoded password to the login handler in /bin/netis.cgi. Attackers can exploit the custom Base64 decoder's lack of output length validation against the fixed-size stack buffer to achieve remote code execution with root privileges, as the Boa web server executes the CGI environment as root.
Weakness: CWE-121
Which versions are affected by CVE-2026-76070?
How do I fix CVE-2026-76070?
No fix has been published for CVE-2026-76070 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-76070 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-76070 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-7gc7-3gxp-v85m.