CVE-2026-21509

KEV
Published: Gen 26, 2026 Last Modified: Feb 11, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 7,8
Source: [email protected]
Attack Vector: local
Attack Complexity: low
Privileges Required: none
User Interaction: required
Scope: unchanged
Confidentiality: high
Integrity: high
Availability: high

Description

AI Translation Available

Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0291
Percentile
0,9th
Updated

EPSS Score Trend (Last 49 Days)

807

Reliance on Untrusted Inputs in a Security Decision

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Confidentiality Access Control Availability Other
Potential Impacts:
Bypass Protection Mechanism Gain Privileges Or Assume Identity Varies By Context
Applicable Platforms
Technologies: Not Technology-Specific, Web Based, Web Server
Likelihood of Exploit: High
View CWE Details
Application

Office Long Term Servicing Channel by Microsoft

Product Information
Vendor Microsoft
Product Office Long Term Servicing Channel
Version 2024
cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office by Microsoft

Product Information
Vendor Microsoft
Product Office
Version 2016
cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office Long Term Servicing Channel by Microsoft

Product Information
Vendor Microsoft
Product Office Long Term Servicing Channel
Version 2021
cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office by Microsoft

Product Information
Vendor Microsoft
Product Office
Version 2019
cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x86:*
Common Platform Enumeration - Standardized vulnerability identification
Application

365 Apps by Microsoft

Product Information
Vendor Microsoft
Product 365 Apps
Version -
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office by Microsoft

Product Information
Vendor Microsoft
Product Office
Version 2016
cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x64:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office Long Term Servicing Channel by Microsoft

Product Information
Vendor Microsoft
Product Office Long Term Servicing Channel
Version 2021
cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:*
Common Platform Enumeration - Standardized vulnerability identification
Application

365 Apps by Microsoft

Product Information
Vendor Microsoft
Product 365 Apps
Version -
cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office by Microsoft

Product Information
Vendor Microsoft
Product Office
Version 2019
cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x64:*
Common Platform Enumeration - Standardized vulnerability identification
Application

Office Long Term Servicing Channel by Microsoft

Product Information
Vendor Microsoft
Product Office Long Term Servicing Channel
Version 2024
cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:*
Common Platform Enumeration - Standardized vulnerability identification
https://www.cisa.gov/known-exploited-vulnerabilities-catalo…
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026…
https://www.vicarius.io/vsociety/posts/cve-2026-21509-detec…
https://www.vicarius.io/vsociety/posts/cve-2026-21509-detection-script-microsof…
https://www.vicarius.io/vsociety/posts/cve-2026-21509-mitig…
https://www.vicarius.io/vsociety/posts/cve-2026-21509-mitigation-script-microso…
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2…
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509