CVE-2026-12495 PUBLISHED

Stack-Based Buffer Overflow in the Mercusys MB115-4G

Assigner: INCIBE
Reserved: 17.06.2026 Published: 27.07.2026 Updated: 27.07.2026

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.

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 9.2

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Mercusys
Product	MB115-4G
Versions	Default: unaffected affected from 1.7.0 to 1.9.0 (incl.)

Solutions

The vulnerability has been fixed by the Mercusys team in version V1_1.9.0.

Credits

Héctor Villar Palacios finder

References

https://www.incibe.es/en/incibe-cert/notices/aviso/stack-based-buffer-overflow-mercusys-mb115-4g

Problem Types

CWE-121 Stack-based buffer overflow CWE