KEV · Actively exploited
CVE-2026-21509
CVE-2026-21509 is actively exploited (CISA KEV catalog) : high severity (CVSS 7.8), 2 tracked apps concerned, none still exposed on their current version.
- Severity (CVSS)
- 7.8
- Exploitation
- Confirmed
- Tracked apps
- 2
- Still exposed
- 0
NVD scale
CISA KEV · EPSS predicts 72.6 %
Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
Attack vector : Local
No privileges required
Show raw CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
72.55%
predictive model; CISA confirms active exploitation
percentile 99.4%
CISA Known Exploited Vulnerability
- Added to KEV
- 2026-01-26
- Remediation deadline
- 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.
- Ransomware
- Unknown (not documented by CISA)
Tracked apps referencing this CVE
For each app: the affected range, the fixing version, and where the tracked app stands today.
-
-
Affected - Fixed in - Latest tracked - undetermined
Vulnerable CPE configurations (16)
| Vendor | Product | Platform | Versions | CPE 2.3 URI |
|---|---|---|---|---|
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x64:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x64:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2016:*:*:*:*:*:x86:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x64:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x64:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x86:* |
| microsoft |
office All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x86:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:* |
| microsoft |
office_long_term_servicing_channel All platforms (wildcard)
|
All platforms (wildcard) | - | cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:* |