Microsoft has shipped the first full patch for an Exchange Server zero-day that attackers have been exploiting since May. The flaw (CVE-2026-42897) is a cross-site scripting bug in Outlook Web Access: an attacker emails a victim, and when the message is opened in OWA, malicious JavaScript runs inside the victim's authenticated session, allowing session-token theft and mailbox impersonation without ever touching the server. It affects Exchange Server 2016, 2019, and Subscription Edition, and CISA added it to its known-exploited list back in May. Until this week only temporary mitigations existed; the June security updates provide the permanent fix.
Trend Micro disclosed a China-aligned espionage cluster called SHADOW-EARTH-053 that has been targeting government and defense organizations across South, East, and Southeast Asia plus one NATO European country since at least December 2024. The group breaks in by exploiting unpatched Microsoft Exchange and IIS servers (using known flaws like ProxyLogon), drops a Godzilla web shell for persistent access, then uses DLL sideloading to load ShadowPad - a long-running Chinese implant. The targeting overlaps with Earth Alux and REF7707, suggesting either a shared operator or shared infrastructure across China-aligned groups. Targets include journalists and activists alongside government agencies.
TrustStrike Labs