CVE-2026-12495 Stack-Based Buffer Overflow in the Mercusys MB115-4G
Unauthenticated attackers can crash the web administration service of Mercusys MB115-4G routers via a stack buffer overflow in the login endpoint.
- 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-2026-12495?
CVE-2026-12495 is a medium-severity memory corruption vulnerability in Mercusys MB115-4G, published on 27 Jul 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Denial-of-service (DoS) vulnerability due to a stack buffer overflow in the http_gdpr_decrypt function of the Mercusys MB115-4G device's web interface. An unauthenticated attacker could exploit this vulnerability by sending a specially crafted request to the /cgi/login endpoint, causing memory corruption and the httpd process to crash, resulting in a denial of service for the web administration service.
Weakness: CWE-121
Which versions are affected by CVE-2026-12495?
How do I fix CVE-2026-12495?
No fix has been published for CVE-2026-12495 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-2026-12495 being exploited?
There is no known exploitation of CVE-2026-12495 in the wild and no public exploit code.
Sources
Also known as GHSA-f8cq-j6x7-pfpx.