Is CVE-2026-31267 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-31267 being exploited in the wild.

How severe is CVE-2026-31267?

Informational severity, with a CVSS score of 4.9, published 9 July 2026.

Which products and versions are affected?

Mercusys MW302R MW302R(EU)_V1_1.4.10 Build 231023 and earlier.

Is there a fix for CVE-2026-31267?

A patch was published on 2026-04-29: Vendor patch released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-31267 attacked?

It is attacked over the network or from the adjacent network, in a network appliance.

Am I affected by CVE-2026-31267?

Check whether you run Mercusys MW302R 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-2026-31267: Mercusys MW302R stack buffer overflow in administrative web interface

CVE-2026-31267 · Severity: info · CVSS 4.9 · Published 2026-07-09

The Mercusys MW302R, a wireless router used for home and small office networking, contains a security flaw in its management interface. An authorized administrator can send a specifically formatted request that causes the device to crash or reboot. This results in a total loss of internet connectivity and network services until the device recovers.

Vendors: Mercusys.

Quick answers

Is CVE-2026-31267 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-31267 being exploited in the wild.
How severe is CVE-2026-31267?: Informational severity, with a CVSS score of 4.9, published 9 July 2026.
Which products and versions are affected?: Mercusys MW302R MW302R(EU)_V1_1.4.10 Build 231023 and earlier.
Is there a fix for CVE-2026-31267?: A patch was published on 2026-04-29: Vendor patch released Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-31267 attacked?: It is attacked over the network or from the adjacent network, in a network appliance.
Am I affected by CVE-2026-31267?: Check whether you run Mercusys MW302R 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 exists within the administrative web interface of the Mercusys MW302R router. The vulnerability is triggered when the web server processes a specially crafted request, leading to control flow manipulation to an arbitrary instruction address. An attacker must be authenticated with administrative privileges to exploit this flaw. Successful exploitation results in a system crash and subsequent denial of service. The issue is fixed in firmware version MW302R(EU)_V1_1.11.10 Build 260327.

Affected products

Mercusys MW302R MW302R(EU)_V1_1.4.10 Build 231023 and earlier

Timeline

2026-04-09: other: CVE reserved
2026-04-29: patched: Vendor patch released
2026-05-06: disclosed: Public disclosure request submitted
2026-07-09: advisory: NVD publication date

References

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