CVE-2026-54998: CWE-863: Incorrect Authorization in Microsoft Microsoft Exchange Online
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
AI Analysis
Technical Summary
This vulnerability, identified as CWE-863 (Incorrect Authorization), exists in Microsoft Exchange Online. It allows an attacker with some level of authorization to escalate their privileges remotely over the network. The CVSS 3.1 base score is 8.8, indicating a high impact on confidentiality, integrity, and availability. Microsoft has published an official fix to address this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized attacker to gain elevated privileges, potentially leading to full compromise of affected Exchange Online environments. This impacts confidentiality, integrity, and availability of the service.
Mitigation Recommendations
An official fix is available from Microsoft. Users should apply the patch provided in the Microsoft security update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54998 to remediate this vulnerability.
CVE-2026-54998: CWE-863: Incorrect Authorization in Microsoft Microsoft Exchange Online
Description
Incorrect authorization in Microsoft Exchange Online allows an authorized attacker to elevate privileges over a network.
CVSS v3.1
Score 8.8high
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability, identified as CWE-863 (Incorrect Authorization), exists in Microsoft Exchange Online. It allows an attacker with some level of authorization to escalate their privileges remotely over the network. The CVSS 3.1 base score is 8.8, indicating a high impact on confidentiality, integrity, and availability. Microsoft has published an official fix to address this issue.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized attacker to gain elevated privileges, potentially leading to full compromise of affected Exchange Online environments. This impacts confidentiality, integrity, and availability of the service.
Mitigation Recommendations
An official fix is available from Microsoft. Users should apply the patch provided in the Microsoft security update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54998 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-16T14:10:05.869Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54998","vendor":"Microsoft"}]
Threat ID: 6a46e7f427e9c797193afcb7
Added to database: 07/02/2026, 22:36:36 UTC
Last enriched: 08/10/2026, 13:33:40 UTC
Last updated: 08/15/2026, 05:17:43 UTC
Views: 123
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