CVE-2026-21260CWE-200

Microsoft Outlook Spoofing Vulnerability

High · published February 10, 2026

CVSS v3.1
7.5
EPSS
2%
Percentile
74.4
In the wild
Unconfirmed
What it is

⚡ An attacker can impersonate anyone over your network through a Microsoft Office Outlook vulnerability! Imagine the chaos that could ensue! Think of this like a clever con artist slipping into a conference and pretending to be someone important — they can spread misinformation and create panic without anyone ever confirming their identity. This vulnerability lets them do exactly that, but through your emails! If exploited, this could lead to serious unauthorized access, allowing attackers to spoof identities and send misleading messages to your contacts. Imagine an attacker sending a fake financial request that looks completely legitimate — it could lead to data breaches or financial losses. The implications can be absolutely devastating!

Put simply

Think of this like a clever con artist slipping into a conference and pretending to be someone important — they can spread misinformation and create panic without anyone ever confirming their identity. This vulnerability lets them do exactly that, but through your emails! This vulnerability in Microsoft Office Outlook exposes sensitive information, enabling unauthorized actors to perform email spoofing over a network, tricking recipients into believing they are communicating with a trusted source.

What to do

If exploited, this could lead to serious unauthorized access, allowing attackers to spoof identities and send misleading messages to your contacts. Imagine an attacker sending a fake financial request that looks completely legitimate — it could lead to data breaches or financial losses. The implications can be absolutely devastating! To protect yourself, ensure that your Outlook is updated to the latest version that addresses this vulnerability. Enable multi-factor authentication (MFA) to add an extra layer of security against email spoofing attacks. Regularly audit your organization's email practices to educate users on identifying suspicious emails. 🛡️ You've got this! By taking these steps, you can lock down your security and keep those pesky attackers at bay! 🔒💪

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
CVSS v4.0
Not supplied
EPSS
0.01521 · 74.4th percentile
Weakness
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor
Published
2026-02-10T17:51Z
EPSS history
Timeline
  • 10 FEB 17:51Z
    Microsoft Outlook Spoofing Vulnerability
    cvelistv5