9.2
CRITICAL CVSS 4.0
CVE-2026-12495
Stack-Based Buffer Overflow in the Mercusys MB115-4G
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.

INFO

Published Date :

July 27, 2026, 12:16 p.m.

Last Modified :

July 27, 2026, 4:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-12495 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 4.0 CRITICAL 0cbda920-cd7f-484a-8e76-bf7f4b7f4516
CVSS 4.0 CRITICAL [email protected]
Solution
Patch the device firmware to fix the stack buffer overflow in http_gdpr_decrypt.
  • Apply firmware updates from the vendor.
  • Ensure the httpd process is monitored.
  • Restrict access to the web interface.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-12495.

URL Resource
https://www.incibe.es/en/incibe-cert/notices/aviso/stack-based-buffer-overflow-mercusys-mb115-4g
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-12495 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-12495 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-12495 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-12495 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jul. 27, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-12495', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-27T14:40:38.739030Z'}
  • New CVE Received by [email protected]

    Jul. 27, 2026

    Action Type Old Value New Value
    Added Affected [{'vendor': 'Mercusys', 'product': 'MB115-4G', 'versions': [{'status': 'affected', 'version': '1.7.0', 'versionType': 'custom', 'lessThanOrEqual': '1.9.0'}], 'defaultStatus': 'unaffected'}]
    Added 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.
    Added CVSS V4.0 AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CWE CWE-121
    Added Reference https://www.incibe.es/en/incibe-cert/notices/aviso/stack-based-buffer-overflow-mercusys-mb115-4g
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.