CVE-2026-21509: CWE-807: Reliance on Untrusted Inputs in a Security Decision in Microsoft Microsoft 365 Apps for Enterprise
CVE-2026-21509 is a high-severity vulnerability in Microsoft 365 Apps for Enterprise version 16. 0. 1 where the software relies on untrusted inputs in a security decision. This flaw allows a local unauthorized attacker to bypass a security feature, potentially leading to full confidentiality, integrity, and availability compromise. A patch is available to address this issue.
AI Analysis
Technical Summary
This vulnerability (CVE-2026-21509) involves Microsoft 365 Apps for Enterprise improperly relying on untrusted inputs when making security decisions. This weakness (CWE-807) enables an attacker with local access to bypass security controls, resulting in high impact on confidentiality, integrity, and availability. The CVSS 3.1 base score is 7.8, reflecting the local attack vector with low complexity, no privileges required, but requiring user interaction. The vendor has released a patch to remediate this issue.
Potential Impact
Successful exploitation allows an unauthorized local attacker to bypass security features in Microsoft 365 Apps for Enterprise, leading to complete compromise of confidentiality, integrity, and availability of the affected system or data. The vulnerability is rated high severity with a CVSS score of 7.8.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Microsoft 365 Apps for Enterprise version 16.0.1 or later to remediate this issue. No additional mitigation guidance is provided or required beyond applying the patch.
CVE-2026-21509: CWE-807: Reliance on Untrusted Inputs in a Security Decision in Microsoft Microsoft 365 Apps for Enterprise
Description
CVE-2026-21509 is a high-severity vulnerability in Microsoft 365 Apps for Enterprise version 16. 0. 1 where the software relies on untrusted inputs in a security decision. This flaw allows a local unauthorized attacker to bypass a security feature, potentially leading to full confidentiality, integrity, and availability compromise. A patch is available to address this issue.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability (CVE-2026-21509) involves Microsoft 365 Apps for Enterprise improperly relying on untrusted inputs when making security decisions. This weakness (CWE-807) enables an attacker with local access to bypass security controls, resulting in high impact on confidentiality, integrity, and availability. The CVSS 3.1 base score is 7.8, reflecting the local attack vector with low complexity, no privileges required, but requiring user interaction. The vendor has released a patch to remediate this issue.
Potential Impact
Successful exploitation allows an unauthorized local attacker to bypass security features in Microsoft 365 Apps for Enterprise, leading to complete compromise of confidentiality, integrity, and availability of the affected system or data. The vulnerability is rated high severity with a CVSS score of 7.8.
Mitigation Recommendations
A patch is available for this vulnerability. It is recommended to apply the official Microsoft update for Microsoft 365 Apps for Enterprise version 16.0.1 or later to remediate this issue. No additional mitigation guidance is provided or required beyond applying the patch.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-30T18:10:54.844Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6977a2884623b1157cab31e4
Added to database: 1/26/2026, 5:21:12 PM
Last enriched: 4/25/2026, 10:21:00 PM
Last updated: 5/8/2026, 3:21:11 PM
Views: 443
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