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 flaw is classified under CWE-835, which pertains to loops with unreachable exit conditions, commonly known as infinite loops. In this case, the MEGACO protocol dissector within Wireshark contains a logic error that causes it to enter an infinite loop when processing certain malformed or maliciously crafted MEGACO protocol data. MEGACO (Media Gateway Control Protocol) is used in telecommunications for controlling media gateways. When Wireshark attempts to dissect such crafted packets, the infinite loop causes the application to become unresponsive, resulting in a denial of service (DoS) condition. The CVSS v3.1 base score is 5.5 (medium severity), reflecting that the attack vector is local (AV:L), requires low attack complexity (AC:L), no privileges (PR:N), but does require user interaction (UI:R) to open the malicious capture or traffic. The vulnerability impacts availability only (A:H), with no confidentiality or integrity effects. There are no known exploits in the wild, and no patches have been published at the time of this report. The vulnerability could be exploited by an attacker who can provide crafted MEGACO traffic to a user running a vulnerable Wireshark version, causing the application to hang and potentially disrupting network analysis or monitoring activities.

For European organizations, the primary impact of CVE-2025-13946 is denial of service on systems running vulnerable versions of Wireshark, particularly those used in telecom, network monitoring, or security analysis environments. This can lead to operational disruptions, delayed incident response, and reduced visibility into network traffic. While the vulnerability does not compromise data confidentiality or integrity, the loss of availability can affect critical network troubleshooting and monitoring tasks. Organizations relying heavily on Wireshark for real-time analysis or forensic investigations may experience workflow interruptions. Additionally, telecom operators and service providers using MEGACO protocol analysis are at higher risk of encountering this issue. The lack of known exploits reduces immediate risk, but the presence of the vulnerability in widely used network analysis tools necessitates caution. In regulated sectors, such as finance or critical infrastructure, any downtime or monitoring gaps could have compliance and security implications.

To mitigate CVE-2025-13946, European organizations should: 1) Avoid opening untrusted or suspicious MEGACO protocol capture files or live traffic streams in affected Wireshark versions. 2) Monitor Wireshark processes for unresponsiveness or hangs during protocol dissection and restart the application if necessary. 3) Implement strict access controls to limit who can run Wireshark and analyze network traffic, reducing exposure to crafted malicious inputs. 4) Use alternative tools or older versions without the vulnerability if immediate patching is not possible, while balancing security risks. 5) Stay alert for official patches or updates from the Wireshark Foundation and apply them promptly once available. 6) Incorporate network-level filtering to block or isolate suspicious MEGACO traffic from untrusted sources. 7) Educate network analysts and security teams about this vulnerability and safe handling of capture files. These measures go beyond generic advice by focusing on operational controls, process monitoring, and proactive traffic filtering specific to the MEGACO protocol context.