https://aretiq.ai/tags/cve-2026-54995/Recent content in Cve-2026-54995 on Aretiq AIHugoen-usThu, 02 Jul 2026 00:00:00 +0000https://aretiq.ai/research/vul260702-cve-2026-54995-microsoft-windows-reliable-multicast-transport-driver-integer-underflow/Thu, 02 Jul 2026 00:00:00 +0000https://aretiq.ai/research/vul260702-cve-2026-54995-microsoft-windows-reliable-multicast-transport-driver-integer-underflow/<h1 id="cve-2026-54995--microsoft-windows-reliable-multicast-transport-driver-integer-underflow">CVE-2026-54995 — Microsoft Windows Reliable Multicast Transport Driver Integer Underflow</h1> <h2 id="1-overview">1. Overview</h2> <p>A vulnerability exists in the Windows Reliable Multicast Transport Driver (rmcast.sys) that implements the Pragmatic General Multicast (PGM) protocol. When processing incoming ODATA packets for a Forward Error Correction (FEC) group, the driver&rsquo;s <code>PgmHandleNewData</code> function can decrement a parity packet counter past zero, causing an unsigned byte to underflow from 0 to 255. This corrupted counter subsequently causes out-of-bounds memory access when the driver attempts FEC decoding with an impossibly large parity count. An unauthenticated remote attacker can send specially crafted PGM multicast packets to a system running a PGM receiver application, potentially achieving kernel-level code execution. Microsoft addressed this vulnerability in the July 2026 security update.</p>