Synology issues critical fix for MailPlus Server vulnerabilities

Synology has has fixed critical vulnerabilities in MailPlus Server, a software package used to run private email infrastructure on Synology NAS devices. The security update fixes three flaws: CVE-2026-13136, stemming from faulty authorization checks, may allow remote attackers to read or write arbitrary files and conduct denial-of-service (DoS) attacks CVE-2026-13135, caused by improper restriction of communication channel to intended endpoints, may allow remote attackers to access internal serv