CVE-2026-5402 is a heap-based buffer overflow vulnerability in the TLS protocol dissector component of Wireshark versions 4.6.0 to 4.6.4. The flaw allows an attacker to cause a denial of service or possibly execute arbitrary code by crafting malicious TLS traffic that triggers the overflow during packet analysis. The vulnerability is identified as CWE-122 and has a high CVSS v3.1 score of 8.8, indicating significant impact on confidentiality, integrity, and availability. No vendor advisory or patch information is currently available, and no known exploits in the wild have been reported.

Successful exploitation can result in denial of service by crashing Wireshark or potentially arbitrary code execution, which could compromise the host running the vulnerable Wireshark version. The vulnerability affects confidentiality, integrity, and availability of the affected system as indicated by the CVSS vector. There are no reports of active exploitation in the wild at this time.

Patch status is not yet confirmed — check the Wireshark Foundation vendor advisory for current remediation guidance. Until an official fix is released, users should consider avoiding use of affected Wireshark versions (4.6.0 to 4.6.4) for analyzing untrusted TLS traffic or use alternative tools. Monitor official Wireshark channels for updates and apply patches promptly once available.