CVE-2026-54998
Microsoft Exchange Online Elevation of Privilege Vulnerability
Incorrect authorization in Microsoft Exchange Online 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
What each source reports
CVE List Score used
Microsoft Exchange Online Elevation of Privilege Vulnerability
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
- Record
CVE-2026-54998- 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
- 2026-11-02
EUVDEUVD-2026-41446
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
- Record
EUVD-2026-41446- 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
- 2026-11-02
GitHub AdvisoriesGHSA-phr2-vr74-whpx
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate...
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
- Record
GHSA-phr2-vr74-whpx- 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 Online allows an authorized attacker to elevate privileges over a network.
- Record
CVE-2026-54998- 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
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | sentinel-aidefense/CVE-2026-54998-exp | 2026-07-04 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-54998 is a high vulnerability (CVSS 8.8) in Microsoft Exchange Online, published July 2, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.78%, the 56th percentile. No source names a fixed version.