CVE-2026-5405 is a heap-based buffer overflow vulnerability in the Remote Desktop Protocol (RDP) dissector component of Wireshark versions 4.6.0 through 4.6.4 and 4.4.0 through 4.4.14. This vulnerability can cause the Wireshark application to crash, leading to denial of service, and may also allow an attacker to execute arbitrary code. The vulnerability is identified as CWE-122 and carries a CVSS 3.1 base score of 7.8, indicating high severity. The vulnerability requires local access (AV:L) with low attack complexity and no privileges required, but user interaction is needed. The vendor has not yet provided an official fix or remediation level, and no known exploits have been reported in the wild.

Successful exploitation of this vulnerability can cause Wireshark to crash, resulting in denial of service. There is also a potential for arbitrary code execution, which could compromise the host running the vulnerable Wireshark versions. The impact affects confidentiality, integrity, and availability as indicated by the CVSS vector.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should consider avoiding opening untrusted RDP traffic captures or running Wireshark with limited privileges to reduce potential impact. Monitor the Wireshark Foundation's advisories for updates and apply patches promptly once available.