Skip to content
Fencer Intel
high 8.8

CVE-2026-77910 json

Microsoft Exchange Server Elevation of Privilege Vulnerability

published 27d ago modified 9d ago also EUVD-2026-100140

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

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

Patch / fix

  • Microsoft Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.077
  • Microsoft Microsoft Exchange Server 2019 Cumulative Update 14 15.02.1544.050
  • Microsoft Microsoft Exchange Server 2019 Cumulative Update 15 15.02.1748.055
  • Microsoft Microsoft Exchange Server Subscription Edition RTM 15.02.2562.056

Is CVE-2026-77910 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
CNA 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Microsoft Microsoft Exchange Server 2016 Cumulative Update 23
  • Microsoft Microsoft Exchange Server 2019 Cumulative Update 14
  • Microsoft Microsoft Exchange Server 2019 Cumulative Update 15
  • Microsoft Microsoft Exchange Server Subscription Edition RTM

Classification

Weakness
Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.