CVE-2026-87696: microsoft microsoft exchange server 2016 cumulative update 23
CVSS: 7.5v3.1HighAwaiting analysis
Published 13-10-2026Last modified 20-10-2026
Vulnerability summary
CVE-2026-87696 is a high (CVSS 7.5) vulnerability in microsoft microsoft exchange server 2016 cumulative update 23. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 30.3% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.38%
0%100%
Low · Change unavailableKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 13-10-2026PublishedVulnerability first disclosed.
- 20-10-2026Last modifiedVulnerability information updated.
Description
Improper verification of cryptographic signature in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
CVSS metrics
2 scores · 2 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CSourcesAll 2 agree
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.38%
Chance of exploitation in the next 30 days
Percentile
30%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
14-10-202620-10-2026
EPSS score0.38%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Microsoft4 products
- microsoft exchange server 2016 cumulative update 23≥ 15.01.0.0, < 15.01.2507.077
- microsoft exchange server 2019 cumulative update 14≥ 15.02.0.0, < 15.02.1544.050
- microsoft exchange server 2019 cumulative update 15≥ 15.02.0.0, < 15.02.1748.055
- microsoft exchange server subscription edition rtm≥ 15.02.0.0, < 15.02.2562.056
1 vendor · 4 products