CVE-2026-21527
UI Spoofing Vulnerability in Microsoft Exchange Server
Publication date: 2026-02-10
Last updated on: 2026-02-11
Assigner: Microsoft Corporation
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| microsoft | exchange_server | 2016 |
| microsoft | exchange_server | 2019 |
| microsoft | exchange_server | 2019 |
| microsoft | exchange_server | to 15.02.2562.037 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-1286 | The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax. |
| CWE-451 | The user interface (UI) does not properly represent critical information to the user, allowing the information - or its source - to be obscured or spoofed. This is often a component in phishing attacks. |
| CWE-345 | The product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is a user interface misrepresentation issue in Microsoft Exchange Server. It allows an unauthorized attacker to perform spoofing over a network by misleading users with incorrect or deceptive information displayed in the user interface.
How can this vulnerability impact me? :
The vulnerability can impact you by enabling an attacker to spoof critical information, potentially leading to unauthorized actions or decisions based on false data. This can compromise the integrity and trustworthiness of communications or operations within Microsoft Exchange Server.
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
How can this vulnerability be detected on my network or system? Can you suggest some commands?
I don't know
What immediate steps should I take to mitigate this vulnerability?
I don't know