CVE-2026-5404 is a classic buffer overflow vulnerability (CWE-120) in the K12 RF5 file parser component of Wireshark versions 4.6.0 through 4.6.4 and 4.4.0 through 4.4.14. The issue arises from copying data into a buffer without verifying the input size, which can lead to a crash of the Wireshark application, causing denial of service. The CVSS 3.1 base score is 4.7, reflecting a medium severity with local attack vector, high attack complexity, no privileges required, and user interaction needed. There is no evidence of exploitation in the wild, and no vendor advisory or patch information is currently provided.

Successful exploitation results in denial of service by crashing the Wireshark application when processing crafted K12 RF5 files. There is no indication of confidentiality or integrity impact. The attack requires local access and user interaction, with high complexity, limiting the likelihood of widespread exploitation.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, users should avoid opening untrusted K12 RF5 files with affected Wireshark versions. Monitor official Wireshark Foundation communications for updates and apply patches promptly once available.