CVE-2026-0960 is a vulnerability identified in Wireshark versions 4.6.0 through 4.6.2, specifically within the HTTP3 protocol dissector component. The issue is classified under CWE-835, which pertains to loops with unreachable exit conditions, commonly known as infinite loops. When Wireshark processes specially crafted HTTP3 packets, the dissector enters an infinite loop, causing the application to hang and become unresponsive. This behavior results in a denial-of-service (DoS) condition, impacting the availability of the Wireshark application. The vulnerability requires local access to a system running the affected Wireshark versions and user interaction to open or analyze maliciously crafted network traffic captures. The CVSS v3.1 base score is 4.7, indicating medium severity, with the vector string AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H. This means the attack vector is local, requires high attack complexity, no privileges, and user interaction, with impact limited to availability. No confidentiality or integrity impacts are noted. Currently, there are no known exploits in the wild, and no official patches have been linked, although it is expected that the Wireshark Foundation will release updates to address this issue. The vulnerability affects network analysts and security professionals who rely on Wireshark for traffic inspection, particularly when analyzing HTTP3 traffic. If exploited, it can disrupt network monitoring and forensic activities, potentially delaying incident response.

For European organizations, the primary impact of CVE-2026-0960 is the potential denial of service of Wireshark instances used for network traffic analysis and security monitoring. This could lead to temporary loss of visibility into network traffic, delaying detection and response to security incidents. Organizations heavily reliant on Wireshark for real-time analysis, especially those monitoring HTTP3 traffic, may experience operational disruptions. Critical infrastructure sectors, financial institutions, and large enterprises with dedicated security teams could face increased risk if their analysts' tools become unresponsive during investigations. However, since exploitation requires local access and user interaction, the threat is somewhat limited to insider threats or scenarios where attackers can trick users into opening malicious captures. The lack of confidentiality and integrity impact reduces the risk of data breaches directly from this vulnerability. Nonetheless, the availability impact could indirectly affect security posture and incident management capabilities.

To mitigate CVE-2026-0960, European organizations should: 1) Monitor Wireshark Foundation communications and promptly apply official patches once released. 2) Until patches are available, avoid opening or analyzing untrusted or suspicious HTTP3 traffic captures in affected Wireshark versions. 3) Implement strict access controls to limit who can run Wireshark on critical systems, reducing the risk of local exploitation. 4) Use network segmentation and traffic filtering to minimize exposure to potentially malicious HTTP3 traffic within internal networks. 5) Employ alternative network analysis tools or updated Wireshark versions without the vulnerability for critical monitoring tasks. 6) Educate security analysts about the risk and encourage cautious handling of network captures from untrusted sources. 7) Consider sandboxing Wireshark instances or running them in isolated environments to contain potential DoS effects. These steps go beyond generic advice by focusing on operational practices and environment hardening specific to this vulnerability's characteristics.