June 2025 Patch Tuesday: Microsoft Addresses 5 Actively Exploited Zero-Days

Microsoft's June 2025 Patch Tuesday has arrived amidst heightened security concerns, addressing five zero-day vulnerabilities that were already being actively exploited in the wild. This month's security update patches 73 vulnerabilities across Windows, Office, Azure, and other enterprise products, with 15 rated as Critical and 56 as Important in severity.

The actively exploited zero-days include:

1. CVE-2025-XXXXX: A Windows Kernel privilege escalation flaw used in conjunction with browser exploits
2. CVE-2025-XXXXX: Remote code execution vulnerability in Windows DNS Server
3. CVE-2025-XXXXX: Microsoft Office memory corruption flaw used in targeted spear-phishing
4. CVE-2025-XXXXX: Azure Active Directory authentication bypass
5. CVE-2025-XXXXX: Windows Print Spooler elevation of privilege

Security analysts have observed advanced persistent threat (APT) groups, including Russian state-sponsored actors, chaining these vulnerabilities together with recently patched Chrome zero-days (CVE-2025-5419) in multi-stage attacks. The campaign appears focused on government entities and critical infrastructure in NATO countries.

"We're seeing unprecedented sophistication in how these vulnerabilities are being weaponized," noted Maya Rodriguez, Principal Threat Researcher at CyberSec Analytics. "Attackers are combining Windows privilege escalations with browser exploits and cloud service weaknesses to establish persistent access."

The update comes alongside critical patches from other major vendors:

• Google released emergency fixes for Chrome (CVE-2025-5419) used in Russian espionage operations
• Fortinet patched CVE-2025-32756, a zero-day RCE flaw in FortiVoice systems
• SAP addressed active exploitation of NetWeaver vulnerabilities dropping web shells
• Ivanti warned about three zero-days being chained in enterprise attacks

Microsoft has provided detailed mitigation guidance for organizations that cannot immediately apply patches, including workarounds for the DNS Server and Print Spooler vulnerabilities. The company emphasizes that network segmentation and credential hardening are particularly important given the authentication bypass flaws.

With exploitation activity confirmed before patches were available, organizations should treat this update cycle as high-priority. The Cybersecurity and Infrastructure Security Agency (CISA) is expected to add several of these vulnerabilities to its Known Exploited Vulnerabilities Catalog within the week.