CVE-2026-3203 is a buffer over-read vulnerability classified under CWE-126 affecting the RF4CE Profile protocol dissector in Wireshark versions 4.4.0 through 4.4.13 and 4.6.0 through 4.6.3. The flaw arises from improper bounds checking when parsing RF4CE protocol data, which can lead to reading beyond the allocated buffer. This causes Wireshark to crash, resulting in a denial of service (DoS) condition. The vulnerability requires that an attacker craft malicious RF4CE protocol packets embedded in a capture file or live traffic that Wireshark processes. Exploitation requires user interaction, such as opening a malicious capture file or monitoring compromised network traffic. The CVSS 3.1 base score is 5.5 (medium severity), with attack vector local (AV:L), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), and impacts availability only (A:H). There are no known exploits in the wild and no patches currently linked, indicating the vulnerability is newly disclosed. The vulnerability primarily affects network analysts and security professionals who use Wireshark for packet inspection and troubleshooting. Since Wireshark is widely used globally in enterprise, government, and research environments, the vulnerability poses a risk of disrupting network monitoring activities if exploited. The lack of confidentiality or integrity impact reduces the risk of data breach or manipulation, but availability loss can hinder incident response and network diagnostics. The vulnerability highlights the importance of cautious handling of untrusted capture files and the need for vendor patches to address the buffer over-read.

The primary impact of CVE-2026-3203 is denial of service due to application crashes when Wireshark processes malformed RF4CE protocol data. This can disrupt network analysis, monitoring, and incident response activities, potentially delaying detection and mitigation of other network threats. Organizations relying heavily on Wireshark for real-time or forensic packet analysis may experience operational interruptions. Since the vulnerability does not affect confidentiality or integrity, it does not directly lead to data leakage or unauthorized data modification. However, the loss of availability in critical network diagnostic tools can indirectly increase risk by impairing security teams' visibility. The requirement for user interaction and local access limits remote exploitation, reducing the attack surface. Nonetheless, attackers with access to network capture files or the ability to inject malicious RF4CE traffic could trigger crashes, especially in environments where Wireshark is used to analyze RF4CE-enabled devices or networks. The absence of known exploits in the wild suggests limited current exploitation but does not preclude future attacks once exploit code becomes available. Overall, the impact is moderate but significant for organizations dependent on Wireshark for network security operations.

1. Avoid opening untrusted or suspicious capture files containing RF4CE protocol data until a patch is available. 2. Run Wireshark with the least privileges necessary to limit the impact of crashes. 3. Use network segmentation and access controls to restrict exposure of Wireshark hosts to untrusted networks or capture files. 4. Monitor vendor announcements and apply security updates promptly once patches addressing CVE-2026-3203 are released. 5. Consider disabling or filtering RF4CE protocol dissector in Wireshark if not required for analysis to reduce attack surface. 6. Employ alternative packet analysis tools or sandbox environments for opening unknown capture files to isolate potential crashes. 7. Educate users on the risks of opening capture files from unverified sources and enforce policies for safe handling of network captures. 8. Implement robust logging and monitoring to detect abnormal Wireshark crashes that may indicate exploitation attempts. These steps go beyond generic advice by focusing on protocol-specific mitigations, privilege management, and operational controls tailored to Wireshark usage scenarios.