Mercusys MB115-4G up to 1.9.0 Web Interface /cgi/login http_gdpr_decrypt stack-based overflow

Summaryinfo

A vulnerability classified as critical was found in Mercusys MB115-4G up to 1.9.0. Affected is the function http_gdpr_decrypt of the file /cgi/login of the component Web Interface. Executing a manipulation can lead to stack-based overflow. The identification of this vulnerability is CVE-2026-12495. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in Mercusys MB115-4G up to 1.9.0 and classified as critical. This vulnerability affects the function http_gdpr_decrypt of the file /cgi/login of the component Web Interface. The manipulation with an unknown input leads to a stack-based overflow vulnerability. The CWE definition for the vulnerability is CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). As an impact it is known to affect integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at incibe.es. This vulnerability was named CVE-2026-12495 since 06/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/27/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Mercusys

Name

• MB115-4G

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9.0

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