The quiet DoS bug in Cisco's email gateway hardening release Cisco's September 2026 hardening release for its email security appliances covers five CVEs. Four of them are the kind of flaw that draws attention: directory escape, authorization bypass, injection. The fifth, CVE-2026-20353, is a resource lifetime control weakness, and it is the one most likely to be left unpatched because its impact looks like ordinary instability rather than a security event. Vulnerability overview ...