CVE Tools

Nearly 22,000 Microsoft Exchange servers remain exposed to critical security flaw (CVE-2026-62911)

Help Net SecurityBy Sinisa Markovic

PoC publicMicrosoft Exchange Server

Our summary

A working exploit for CVE-2026-62911 has appeared online, leaving nearly 22,000 instances of Microsoft Exchange Server vulnerable to a critical authentication bypass. This flaw allows attackers to elevate privileges over the network, with the United States and Germany reporting the highest concentration of unpatched systems. Microsoft issued a fix on August 11, 2026, following disclosure by Orange Tsai in collaboration with Trend Micro’s Zero Day Initiative.

Read at Help Net Security

Help Net Security publishes this story on its own site; we link to it rather than reprint it.

Worried this affects your company?

Discuss a security assessment of your internet-facing systems. Scope agreed before testing.

Check my exposure

We use analytics cookies to see which pages and articles actually help people. Decline and none of them run — the site works the same. What we store