KDDI Data Breach Impacts up to 14.2 Million Email Accounts at Six ISPs

A SecurityAffairs roundup covering multiple high-impact incidents and advisories: KDDI disclosed a third‑party software breach exposing up to 14.2 million email accounts across six Japanese ISPs; JFrog published a DirtyClone Linux kernel privilege escalation (CVE-2026-43503) with an 8.8 CVSS and working exploit; CISA added Cisco and PTC Windchill/FlexPLM flaws (including CVE-2026-12569) to its Known Exploited Vulnerabilities catalog; the FBI/CISA warned Russian intelligence actors are targeting Signal backup/recovery keys for message access and account takeover; Microsoft detailed a phishing/”