Microsoft Exchange Server 2019 Cumulative Update 5

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.

Product reference — Microsoft Exchange Server 2019 Cumulative Update 5 by Microsoft · sector: Operating Systems & Platforms. Cumulative disclosure record for this product across the archive.

Product totals

Disclosures & known-exploited
	All-time	YTD
CVEs	4	0
KEV entries	4	0

Rate & severity
KEV/100	Med CVSS	Med EPSS	C	H	M	L
100.0	7.8	.9698	1	3	0	0

KEV/100 = KEV entries ÷ CVEs × 100. Med CVSS / Med EPSS are medians over this product's disclosures. C/H/M/L = disclosures by CVSS severity band.

Monthly disclosures

Trend (by first-seen month, full archive): █▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁

Last 12 months (new CVEs by first-seen day)
Month	New CVEs
2025-09	0
2025-10	0
2025-11	0
2025-12	0
2026-01	0
2026-02	0
2026-03	0
2026-04	0
2026-05	0
2026-06	0
2026-07	0
2026-08	0

Notable CVEs

Ranked by the published formula: KEV → EPSS → CVSS → CVE ID.

Notable (ranked)
CVE	CVSS	EPSS %ile	Severity	KEV	First seen
CVE-2021-26855	9.1	100.0	CRITICAL	YES	2021-11-03
CVE-2021-27065	7.8	100.0	HIGH	YES	2021-11-03
CVE-2021-26857	7.8	99.8	HIGH	YES	2021-11-03
CVE-2021-26858	7.8	99.8	HIGH	YES	2021-11-03

Recent CVEs

Most recently seen
CVE	CVSS	EPSS %ile	Severity	KEV	First seen
CVE-2021-27065	7.8	100.0	HIGH	YES	2021-11-03
CVE-2021-26857	7.8	99.8	HIGH	YES	2021-11-03
CVE-2021-26858	7.8	99.8	HIGH	YES	2021-11-03
CVE-2021-26855	9.1	100.0	CRITICAL	YES	2021-11-03

KEV entries

CISA Known Exploited Vulnerabilities (newest addition first)
CVE	KEV added	CVSS	EPSS %ile	Severity
CVE-2021-27065	2021-11-03	7.8	100.0	HIGH
CVE-2021-26857	2021-11-03	7.8	99.8	HIGH
CVE-2021-26858	2021-11-03	7.8	99.8	HIGH
CVE-2021-26855	2021-11-03	9.1	100.0	CRITICAL

Vendor: Microsoft — all products and the full vendor record.

Methodology

A product is a (vendor, product) pair as named in the affected-product data. Rate statistics are arithmetic over published figures. Counts key to first-seen day. Raw counts are not comparable across products; this is a reference page assembled from the public record, not a ranking by our judgment.