CVE-2026-63890

A flaw was found in the Linux kernel's Fibre Channel over Ethernet (FCoE) module. An unauthenticated attacker on the same Layer 2 (L2) network segment could send a specially crafted FCoE Initialization Protocol (FIP) frame with a malformed descriptor. This could lead to an infinite loop, causing a denial of service (DoS) by blocking all further FIP communication on the affected controller.

A malformed FIP CVL frame can make the FCoE controller CVL descriptor walker loop forever because a non critical descriptor with fip_dlen 0 advances the descriptor cursor by zero bytes. An unauthenticated L2 peer on the FCoE control VLAN can trigger this against affected fcoe, qedf, or bnx2fc initiators by sending a crafted FIP frame. For the CVSS the PR:N is used because no victim side account or local code execution is needed once the attacker can transmit on the adjacent FCoE control network. The issue is adjacent network reachable rather than Internet remote, so AV:A is used. Impact is denial of service because FIP receive work can be blocked indefinitely and later FIP frames for that controller may not be processed. No memory corruption, information disclosure, or privilege escalation primitive is indicated by the code path.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.