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TI-2026-39705 Aliases CVE-2026-54998GHSA-phr2-vr74-whpx

Microsoft Exchange Online Elevation of Privilege Vulnerability

Priority MEDIUM 41CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Privilege escalation
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from Microsoft.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00778 56th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft Exchange Online-—No fix listedCNA
  • Microsoft Exchange Online VendorMicrosoft Affected - Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:exchange_online:-:*:*:*:*:*:*:*not specified by NVDVulnerableMicrosoft
  • cpe:2.3:a:microsoft:exchange_online:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·Microsoft

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Elevation of Privilege
Exploited
No
Publicly disclosed
No
Exploitability
—

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54998
  2. 2026-10-03 Alias added: GHSA-phr2-vr74-whpx

References

Patch 1

  • TI-2026-46891 Microsoft Exchange Online Elevation of Privilege Vulnerability CVSS 3.1CRITICAL 10.0
  • TI-2026-40564 Microsoft Exchange Online Tampering Vulnerability CVSS 3.1CRITICAL 10.0
  • TI-2026-35936 Microsoft Exchange Online Information Disclosure Vulnerability CVSS 3.1CRITICAL 9.1
  • TI-2026-35939 Microsoft Exchange Online Elevation of Privilege Vulnerability CVSS 3.1CRITICAL 9.6

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences