{"id":"AZL-90627","summary":"CVE-2026-53181 affecting package kernel for versions less than 6.6.143.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: fix sk_ack_backlog leak on failed handshake\n\nWhen vmci_transport_recv_connecting_server() returns an error,\nvmci_transport_recv_listen() calls vsock_remove_pending() but never\ncalls sk_acceptq_removed(). This leaves sk_ack_backlog incremented\npermanently.\n\nRepeated handshake failures (malformed packets, queue pair alloc\nfailure, event subscribe failure) cause sk_ack_backlog to climb\ntoward sk_max_ack_backlog. Once it reaches the limit the listener\npermanently refuses all new connections with -ECONNREFUSED, a\nsilent denial of service requiring a process restart to recover.\n\nThe two existing sk_acceptq_removed() calls in af_vsock.c do not\ncover this path: line 764 checks vsock_is_pending() which returns\nfalse after vsock_remove_pending(), and line 1889 is only reached\non successful accept().\n\nFix by balancing sk_acceptq_added() with sk_acceptq_removed() on\nthe error path.","modified":"2026-08-28T17:48:06.114292541Z","published":"2026-06-25T09:16:35Z","upstream":["CVE-2026-53181"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53181"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.143.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-90627.json"}}],"schema_version":"1.9.0"}