News, updates, trends and the latest
info you need to know about IT

Overview
Konami’s Metal Gear Online 3 video game contains a heap-based buffer overflow that can be triggered by an input‑validation vulnerability that allows match hosts to remotely execute arbitrary code on lobby members’ machines through specially crafted data.
Description
Metal Gear Online 3 is an online 8 vs. 8 competitive shooter game that uses Steam Matchmaking to handle its multiplayer lobbies and matches. As detailed in CVE‑2026‑19874, version 1.1.2.8 of Metal Gear Online 3 (Steam AppID 287700) contains an input‑validation vulnerability in the processing of Steam lobby metadata related to the player‑removal feature. The game tracks a lobby field (kick_num) indicating the number of players designated for removal, along with corresponding Steam ID entries of each kicked player (kicked_id_%i). When joining a lobby, the player’s client parses these fields to check whether its own Steam ID is on the list, and if so, the player is prevented from joining the match.
The function responsible for parsing this lobby data does not validate the kick_num value against the size of the fixed‑length buffer allocated for kicked player identifiers. Supplying a kick_num value larger than the buffer capacity results in out‑of‑bounds writes into adjacent memory. The memory region immediately following this buffer contains internal Steamworks callback handler structures that store function pointers and callback arguments for processing lobby data changes, messages, and other related events. By manipulating the overflow, an attacker can corrupt these handler structures and redirect callback execution, resulting in control‑flow hijacking on affected client systems. The vulnerability can be triggered automatically when a client joins a lobby controlled by an attacker.
Impact
Exploitation of this vulnerability may allow remote code execution on affected clients. Initial control‑flow hijacking provides access only to existing in‑process code; however, the Metal Gear Online 3 binary includes Denuvo‑protected regions mapped with read‑write‑execute (RWX) permissions. These regions permit runtime injection of attacker‑supplied code, significantly increasing the severity of the issue. An attacker hosting a lobby can achieve code execution on any client that joins, without requiring further interaction from the victim. Additionally, because host privileges are automatically reassigned to another lobby participant when the current host exits, an attacker can obtain host control during an active match and subsequently deliver the malicious lobby data to all connected players. This enables compromise of multiple systems through a single exploitation event.
Solution
As of this writing, Konami has not released patch notes or an advisory that specifically addresses this vulnerability, but a fix was included in version 1.1.2.9 of the Metal Gear Online 3 executable, mgsvmgo.exe. The patch also iterated the server and lobby version numbers from 15 to 16 and 150 to 160, respectively, to prevent players on older versions from accessing the online services.
This is the latest patch that fixed the vulnerability:
https://steamdb.info/patchnotes/24176213/
The full patch list can be found here:
https://steamdb.info/app/287700/patchnotes/
Acknowledgements
Thank you to Alice Cecchetto for reporting this vulnerability. This document was written by Bob Kemerer.

Overview
The Calix GS7 XGS GS5239XG router running firmware EXOS/6.6.47 contains a missing authentication vulnerability that exposes its UPnP (Universal Plug and Play) WANIPConnection service on the public WAN interface.
Description
Calix GS7 XGS GS5239XG is a residential gateway that provides routing, NAT, and firewall functionality for home networks. The device includes the Universal Plug and Play (UPnP) service implemented via MiniUPnPd 2.3.7, a lightweight software program that provides features such as automatic port forwarding for applications and devices on the LAN. By default, the UPnP service is exposed on the device’s WAN interface and does not require authentication.
CVE-2026-75501 In affected firmware versions, the router binds its UPnP WANIPConnection SOAP service to the public WAN interface on TCP port 5000. Because the service does not require authentication when accepting SOAP requests, a remote attacker can obtain full access to the router’s critical UPnP functions including adding, deleting, and enumerating NAT port mappings.
Impact
CVE-2026-75501 enables an unauthenticated, remote attacker to remotely query and manipulate existing NAT mappings. By exploiting this vulnerability to create arbitrary port-forwarding rules on the router, an attacker can bypass NAT and firewall protections, exposing internal LAN devices to the public internet. Because the Calix router is typically provisioned with its default UPnP-enabled configuration, this issue poses significant risk to residential users with network-connected internal devices such as security cameras, network-attached storage (NAS), and other IoT appliances.
Solution
Unfortunately, the CERT/CC was unable to reach Calix to coordinate this vulnerability. Until a vendor patch is available, users can reduce exposure by disabling UPnP on the router’s administrative interface. If the UPnP setting is unavailable or locked, it may be necessary to contact your ISP to request its deactivation at the carrier level. Alternatively, filtering inbound traffic to TCP port 5000, either via the router itself, a secondary firewall, or through your ISP, can prevent external hosts from reaching the WANIPConnection service.
Acknowledgements
Thanks to Brian Khan Quintana for researching and reporting this vulnerability. This document was written by Molly Jaconski.

Overview
RDK Central RDK-B WebUI version, rdkb-2025q4-kirkstone, contains multiple vulnerabilities involving memory corruption, improper authentication, race conditions, and insufficient input validation. An attacker with network access to an affected WebUI may be able to bypass authentication, obtain administrative access, cause a denial-of-service condition, or corrupt memory within underlying RDK-B processes. Under certain conditions, this memory corruption may potentially be leveraged for arbitrary code execution.
Description
RDK-B (Reference Design Kit for Broadband) is an open-source software platform used in broadband gateways and related networking devices. The RDK-B WebUI provides a web-based interface for configuring and administering an RDK-B device. Five vulnerabilities have been identified in the RDK-B WebUI.
CVE-2026-19505JWT (JSON Web Token) authentication in javascript-templates/source/jst_functions.c does not correctly verify whether a token’s cryptographic signature is valid. The application treats both a valid signature and an invalid signature as successful verification because it incorrectly checks the return value from OpenSSL’s EVP_VerifyFinal() function.
A remote, unauthenticated attacker can craft a JWT with an invalid signature that is still accepted by the WebUI. Successful exploitation allows the attacker to log in as the privileged user and gain administrative access to the device.
CVE-2026-19506 The login process in /usr/www2/check.jst uses a shared value to store the result of password verification. Because this value is shared between multiple requests, the application may return one user’s authentication result to another user’s session.
An unauthenticated attacker can send a login request at the same time a legitimate administrator logs in. If the requests are timed correctly, the attacker’s session may receive the administrator’s successful authentication result, allowing access to the WebUI without knowing the correct password.
CVE-2026-19507 The login handler in /usr/www2/check.jst does not limit the length of the password submitted by a user. The application performs SHA-256 hashing on the entire supplied password before rejecting the login attempt.
A remote, unauthenticated attacker can submit very large password values to consume excessive CPU resources. Repeated requests can make the WebUI and related services slow or unresponsive, resulting in a denial-of-service condition.
CVE-2026-19508 The data parser in javascript-templates/source/jst_post.c does not properly validate malformed input before processing it in memory. A remote, unauthenticated attacker can send a specially crafted request that causes the Duktape WebUI (https://duktape.org/) process to access or modify memory incorrectly.
During data parser processing and later during Duktape memory cleanup, indicating that application memory can be corrupted. An attacker may be able to use this vulnerability to cause a denial-of-service and potentially execute arbitrary code, although code execution has not been demonstrated.
CVE-2026-19509 The ajaxSet_wireless_network_configuration.jst handler does not properly validate the ssid_number value before passing it to the RDK-B routing service.
An authenticated administrator can supply an abnormally large value that causes memory corruption in the native rtrouted process. This condition can crash rtrouted and trigger an RBus service restart. Successful exploitation can cause a denial-of-service. Because the flaw results in native memory corruption, arbitrary code execution may also be possible.
Impact
A remote, unauthenticated attacker with network access to the RDK-B WebUI may be able to bypass authentication and obtain administrative access to the device. An unauthenticated attacker may also cause memory corruption or resource exhaustion, resulting in denial-of-service.
An authenticated administrator may be able to trigger memory corruption in the privileged rtrouted process and result in arbitrary code execution.
Successful exploitation of one or more of these vulnerabilities could result in unauthorized administrative access, modification of device configuration, loss of availability, or potentially execution of attacker-controlled code on an affected device.
Solution
Unfortunately, RDK Central was unreachable to coordinate these vulnerabilities. Until an update is available, administrators should restrict access to the RDK-B WebUI to trusted management networks and authorized hosts. The administrative interface should not be exposed directly to the Internet or other untrusted networks.
Acknowledgements
Thanks to Mikołaj Pisula and Michał Bernacki for researching and reporting these vulnerabilities. This document was written by Michael Bragg.