Is CVE-2026-12495 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-12495 being exploited in the wild.

How severe is CVE-2026-12495?

Informational severity, with a CVSS score of 9.2, published 27 July 2026.

Which products and versions are affected?

Mercusys MB115-4G 1.7.0 through 1.9.0.

Is there a fix for CVE-2026-12495?

A patch was published on 2026-07-27: Fixed in version V1_1.9.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-12495 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-12495?

Check whether you run Mercusys MB115-4G at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-12495: Mercusys MB115-4G stack buffer overflow in http_gdpr_decrypt

CVE-2026-12495 · Severity: info · CVSS 9.2 · Published 2026-07-27

A security vulnerability has been identified in the Mercusys MB115-4G wireless router, a device used to provide internet connectivity in homes and small offices. An attacker can exploit this flaw to crash the router's web management interface, preventing administrators from logging in or changing settings. This could disrupt network management operations and require a manual reboot of the device to restore access.

Vendors: Mercusys.

Quick answers

Is CVE-2026-12495 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-12495 being exploited in the wild.
How severe is CVE-2026-12495?: Informational severity, with a CVSS score of 9.2, published 27 July 2026.
Which products and versions are affected?: Mercusys MB115-4G 1.7.0 through 1.9.0.
Is there a fix for CVE-2026-12495?: A patch was published on 2026-07-27: Fixed in version V1_1.9.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-12495 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-12495?: Check whether you run Mercusys MB115-4G at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A stack-based buffer overflow (CWE-121) exists in the 'http_gdpr_decrypt' function of the Mercusys MB115-4G web interface. The vulnerability is triggered when the '/cgi/login' endpoint receives a specially crafted request, leading to memory corruption. An unauthenticated remote attacker can exploit this to crash the 'httpd' process, resulting in a denial-of-service (DoS) for the web administration service. The issue affects firmware versions 1.7.0 through 1.9.0 and has been addressed in version V1_1.9.0.

Affected products

Mercusys MB115-4G 1.7.0 through 1.9.0

Timeline

2026-07-27: advisory
2026-07-27: patched: Fixed in version V1_1.9.0

References

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

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