8.8

CVE-2026-77910: microsoft microsoft exchange server 2016 cumulative update 23 Incorrect Authorization

CVSS: 8.8v3.1HighAwaiting analysis
Published 13-10-2026Last modified 20-10-2026
Open JSON

Vulnerability summary

CVE-2026-77910 is a high (CVSS 8.8) Incorrect Authorization vulnerability in microsoft microsoft exchange server 2016 cumulative update 23. EPSS estimates a 0.77% chance of exploitation in the next 30 days, higher than 54.6% of scored vulnerabilities.

Overall risk
35/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.77%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 13-10-2026
    PublishedVulnerability first disclosed.
  2. 20-10-2026
    Last modifiedVulnerability information updated.

Description

Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.77%

Chance of exploitation in the next 30 days

Percentile

55%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

14-10-202620-10-2026
EPSS score
0.77%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Microsoft4 products

1 vendor · 4 products

References

1 links