CVE-2026-21509 (GCVE-0-2026-21509)
Vulnerability from cvelistv5
Published
2026-01-26 17:06
Modified
2026-04-01 13:49
Severity ?
VLAI Severity ?
EPSS score ?
CWE
- CWE-807 - Reliance on Untrusted Inputs in a Security Decision
Summary
Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
References
| URL | Tags | ||||
|---|---|---|---|---|---|
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Impacted products
| Vendor | Product | Version | ||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise |
Version: 16.0.1 < https://aka.ms/OfficeSecurityReleases |
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CISA Known Exploited Vulnerability
Data from the CISA Known Exploited Vulnerabilities Catalog
Date added: 2026-01-26
Due date: 2026-02-16
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Used in ransomware: Unknown
Notes: Please adhere to Microsoft’s recommended guidelines to address this vulnerability. Implement all final mitigations provided by the vendor for Office 2021, and apply the interim corresponding mitigations for Office 2016 and Office 2019 until the final patch becomes available. For more information please see: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509 ; https://nvd.nist.gov/vuln/detail/CVE-2026-21509
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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