Microsoft released its November 2026 Security Updates, and JPCERT/CC said in an alert dated November 11, 2026 that one of the patched flaws, CVE-2026-124194 in Outlook, has been confirmed exploited in the wild.
What Microsoft patched
Microsoft released its November 2026 Security Updates to address vulnerabilities in its products, JPCERT/CC said in an alert dated November 11, 2026.
According to JPCERT/CC, attackers leveraging these vulnerabilities may be able to execute arbitrary code remotely or obtain sensitive information.
The Outlook flaw exploited in the wild
JPCERT/CC said that, according to Microsoft, one of the vulnerabilities has been confirmed to be exploited in the wild: CVE-2026-124194, a Microsoft Outlook spoofing vulnerability.
Microsoft said that if exploited, the vulnerability could cause Outlook to connect to an attacker-controlled server without displaying the usual security warning when a user opens a specially crafted message file, potentially resulting in the disclosure of authentication credentials.
JPCERT/CC noted that the vulnerability is classified as CWE-356: Product UI does not Warn User of Unsafe Actions.
What JPCERT/CC advises
JPCERT/CC said to apply the security update programs through Microsoft Update, Windows Update and similar channels, and pointed readers to the Microsoft Update Catalog and a Windows Update FAQ.
The alert also refers readers to Microsoft's release notes and to the latest information provided by Microsoft.
What to do
- Apply Microsoft's November 2026 security updates through Microsoft Update, Windows Update or similar channels, JPCERT/CC says.
- The updates are also available from the Microsoft Update Catalog.
- JPCERT/CC points to Microsoft's Windows Update FAQ for questions about Windows Update.
- JPCERT/CC says to refer to the latest information provided by Microsoft.
Key facts and where they come from
- Microsoft released November 2026 Security Updates to fix vulnerabilities in its products.
Microsoft has released November 2026 Security Updates to address the vulnerabilities in their products.
- According to JPCERT/CC, attackers exploiting the patched vulnerabilities may be able to run arbitrary code remotely or obtain sensitive information.
Attackers leveraging these vulnerabilities may be able to execute arbitrary code remotely or obtain sensitive information, etc.
- Microsoft confirmed that one of the patched vulnerabilities is being exploited in the wild.
According to Microsoft, among the vulnerabilities, the following vulnerability has been confirmed to be exploited in the wild.
- The exploited flaw is CVE-2026-124194, described as a Microsoft Outlook spoofing vulnerability.
CVE-2026-124194 Microsoft Outlook Spoofing Vulnerability
- Microsoft said exploitation could make Outlook connect to an attacker-controlled server with no usual security warning when a specially crafted message file is opened.
this vulnerability could cause Outlook to connect to an attacker-controlled server without displaying the usual security warning when a user opens a specially crafted message file
- The flaw could potentially result in disclosure of authentication credentials.
potentially resulting in the disclosure of authentication credentials
- JPCERT/CC said the vulnerability is classified as CWE-356, meaning the product UI does not warn the user of unsafe actions.
This vulnerability is classified as CWE-356: Product UI does not Warn User of Unsafe Actions
- JPCERT/CC's remediation advice is to apply the security updates through Microsoft Update, Windows Update or similar channels.
Please apply the security update programs through Microsoft Update, Windows Update, etc.
