Microsoft's September 2026 Patch Tuesday addressed multiple critical Linux kernel vulnerabilities in Azure Linux 3.0, including CVE-2026-89526 (CVSS 9.8) in the svcrdma subsystem allowing remote unauthenticated out-of-bounds memory access, and CVE-2026-89653 (CVSS 9.8) in the Ceph filesystem component. Both affect the azl3 kernel 6.6.150.1-1 and require immediate patching.