Microsoft Exchange Server ↗
ℹ On-premises Exchange Server only. Exchange Online (Microsoft 365) is a cloud service patched by Microsoft and is not covered here.
Summary iPlain-English security verdict for Microsoft Exchange Server, generated from its current health score, actively-exploited vulnerabilities, and latest supported version.
Microsoft Exchange Server currently scores 20/100 — critical, with active exploitation. 20 of its known vulnerabilities are being actively exploited in the wild (CISA KEV), including CVE-2020-0688. The latest supported release is 15.2.2562.41. Upgrade immediately and review your exposure to the actively-exploited CVEs below. Note: this product is assessed at the product level on recent (365-day) activity rather than an exact per-version match, so it is never marked a confident "healthy".
Disclosure trend iNew CVEs published for Microsoft Exchange Server each year (NVD). A higher bar means more disclosures that year — more scrutiny, not necessarily less safe.
⚠ 14 of its known vulnerabilities are linked to ransomware campaigns (CISA KEV).
Patch priority — what to act on iThe issues to fix first — actively exploited (CISA KEV) first, then by exploitation probability (EPSS), then severity. Each row's "→ fixed in" is the earliest version that patches it; "see advisory" means no fixed version is published.
Most urgent first — actively exploited, then likeliest to be exploited.
CVE-2020-0688 HIGH ● exploited ⚠ ransomware Improper authentication EPSS 94% → see advisory CVE-2021-26855 CRITICAL ● exploited ⚠ ransomware Server-side request forgery (SSRF) EPSS 94% → see advisory CVE-2021-34473 CRITICAL ● exploited ⚠ ransomware Server-side request forgery (SSRF) EPSS 94% → see advisory CVE-2022-41040 HIGH ● exploited ⚠ ransomware Server-side request forgery (SSRF) EPSS 94% → see advisory CVE-2021-27065 HIGH ● exploited ⚠ ransomware Path traversal EPSS 94% → see advisory CVE-2021-34523 CRITICAL ● exploited ⚠ ransomware EPSS 94% → see advisory CVE-2021-31207 MEDIUM ● exploited ⚠ ransomware Unrestricted file upload EPSS 94% → see advisory CVE-2022-41080 HIGH ● exploited ⚠ ransomware EPSS 94% → see advisory CVE-2021-33766 HIGH ● exploited EPSS 94% → see advisory CVE-2021-42321 HIGH ● exploited ⚠ ransomware EPSS 94% → see advisory CVE-2020-17144 HIGH ● exploited Insecure deserialization EPSS 92% → see advisory CVE-2018-8581 HIGH ● exploited ⚠ ransomware EPSS 92% → see advisoryVersions & lifecycle iWhen each release line stops receiving security patches (end-of-life). After EOL there are no more fixes — plan upgrades before these dates.
How long each Microsoft Exchange Server release line is supported — and when it sunsets.
ℹ product-level posture (last 365d); exact per-version verdict pending precise version mapping