CVE-2026-77910
Microsoft Exchange Server Elevation of Privilege Vulnerability
CVE-2026-77910 is a high vulnerability (CVSS 8.8) in Microsoft Exchange Server 2016 Cumulative Update 23, published October 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.87%, the 59th percentile. No source names a fixed version.
- Severity
- 8.8 HighCVSS 3.1, CVE List
- Exploit chance
- 0.87%EPSS, 59th percentile
- Exploitation
- None knownNot on CISA’s or ENISA’s lists
- Fixed in
- No fix listedNo source names one
Description
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
Affected products
What each source reports
CVE List Score used
Microsoft Exchange Server Elevation of Privilege Vulnerability
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- Record
CVE-2026-77910- CVSS 3.1
- 8.8 High
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 - Weakness
- CWE-863
- Updated
- 2026-11-10
EUVDEUVD-2026-100140
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- Record
EUVD-2026-100140- CVSS 3.1
- 8.8 High
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 - Updated
- 2026-11-10
GitHub AdvisoriesGHSA-8324-3q3h-54w9
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate...
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- Record
GHSA-8324-3q3h-54w9- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-863
- Updated
- 2026-11-02
NVD
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- Record
CVE-2026-77910- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-863
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | CVE List | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.