Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Microsoft Exchange Server Spoofing Vulnerability
AV AC PR UI S C I A CVSS EPSS %ile KEV
N L N R C L L N 6.1 .0031 23.5 —
AFFECTED
Product Versions Fixed
Microsoft Exchange Server 2016 Cumulative Update 23 15.01.0.0 – —
Microsoft Exchange Server 2019 Cumulative Update 14 15.02.0.0 – —
Microsoft Exchange Server 2019 Cumulative Update 15 15.02.0.0 – —
Microsoft Exchange Server Subscription Edition RTM 15.02.0.0 – —
TIMELINE
May 12 Reserved by microsoft
Jun 9 Published (CNA: microsoft)
Jul 28 RESCORED — CVE-2026-45501 (Microsoft Exchange Server 2016 Cumulative Update 23). CVSS 6.5 → 6.1 (NVD).
Description
Server-side request forgery (ssrf) in Microsoft Exchange Server allows an authorized attacker to perform spoofing over a network.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| May 12, 2026 | Reserved | Reserved by microsoft |
| June 9, 2026 | Published | Published (CNA: microsoft) |
| July 28, 2026 | RESCORED | RESCORED — CVE-2026-45501 (Microsoft Exchange Server 2016 Cumulative Update 23). CVSS 6.5 → 6.1 (NVD). |
Affected
Affected products and packages — 4 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 23 | — | 15.01.0.0 | — |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 14 | — | 15.02.0.0 | — |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 15 | — | 15.02.0.0 | — |
| Microsoft | Microsoft Exchange Server Subscription Edition RTM | — | 15.02.0.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-45501 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.