CVE-2025-13946 is a vulnerability identified in the Wireshark network protocol analyzer, specifically affecting versions 4.4.0 through 4.4.11 and 4.6.0 through 4.6.1. The issue arises from a flaw in the MEGACO protocol dissector, where a loop with an unreachable exit condition (classified under CWE-835) causes the application to enter an infinite loop when processing specially crafted MEGACO packets. MEGACO (Media Gateway Control Protocol) is used in telecommunications for controlling media gateways. When Wireshark attempts to dissect such maliciously crafted packets, it fails to exit the loop, causing the application to hang and resulting in a denial of service (DoS) condition. The vulnerability requires local access and user interaction, as the attacker must provide a malicious capture file or network traffic for analysis. The CVSS 3.1 base score is 5.5 (medium severity), reflecting the limited attack vector (local), low complexity, no privileges required, but requiring user interaction. The impact is limited to availability, with no confidentiality or integrity compromise. No patches or exploits are currently publicly available, but the vulnerability is published and should be addressed proactively. Given Wireshark's widespread use in network diagnostics and security analysis, this vulnerability could disrupt operations where Wireshark is used to analyze network traffic, particularly in telecom environments where MEGACO is relevant.

For European organizations, the primary impact is denial of service on systems running vulnerable versions of Wireshark, potentially disrupting network analysis and troubleshooting activities. This can delay incident response and forensic investigations, especially in telecom operators, ISPs, and enterprises with dedicated network security teams. Since MEGACO is a protocol used in telecom infrastructure, organizations involved in media gateway management or telecom network monitoring are at higher risk. The unavailability of Wireshark during critical analysis could hinder timely detection of other threats. However, the vulnerability does not lead to data breaches or unauthorized access, limiting its impact to operational disruption. The requirement for local access and user interaction reduces the risk of remote exploitation but does not eliminate insider threat or accidental exposure risks. European telecom providers and cybersecurity teams relying on Wireshark for packet analysis are the most affected stakeholders.

1. Immediately avoid opening untrusted or suspicious capture files containing MEGACO traffic in affected Wireshark versions. 2. Employ sandboxing or isolated virtual machines for analyzing unknown network captures to contain potential hangs. 3. Monitor Wireshark project announcements for patches addressing this vulnerability and apply updates promptly once available. 4. Implement strict access controls to limit who can run Wireshark on critical systems, reducing the risk of accidental or malicious exposure to crafted captures. 5. Use alternative packet analysis tools or older stable versions not affected by this vulnerability if immediate patching is not possible, ensuring they support necessary protocols. 6. Educate network analysts and security personnel about the risk of crafted MEGACO packets causing application hangs to increase vigilance. 7. Consider automated detection of malformed MEGACO traffic upstream to prevent malicious packets from reaching analysis environments.