CVE-2026-21511

HIGH EPSS 88.1%
Published Feb 10, 20264mo ago · Modified Jun 17, 20262w ago
7.5 CVSS 3.1
High
Find Similar
Published Feb 10, 2026 4mo ago
Last Modified Jun 17, 2026 2w ago

Description

Deserialization of untrusted data in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity None
Availability None

Threat Intelligence

EPSS Exploit Probability
88.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-502 Deserialization of Untrusted Data Validation

Affected Products 15

VendorProductVersionRange
microsoft365_apps*any
microsoft365_apps*any
microsoftoffice2019any
microsoftoffice2019any
microsoftoffice_long_term_servicing_channel2021any
microsoftoffice_long_term_servicing_channel2021any
microsoftoffice_long_term_servicing_channel2021any
microsoftoffice_long_term_servicing_channel2024any
microsoftoffice_long_term_servicing_channel2024any
microsoftoffice_long_term_servicing_channel2024any
microsoftsharepoint_server* <16.0.19127.20518
microsoftsharepoint_server2016any
microsoftsharepoint_server2019any
microsoftword2016any
microsoftword2016any

References 1

  • msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21511
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.