Quick answers
- Is CVE-2026-41100 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-41100 being exploited in the wild.
- How severe is CVE-2026-41100?
- Medium severity, with a CVSS score of 4.4, published 12 May 2026.
- Which products and versions are affected?
- Microsoft Copilot M365 Copilot.
- Is there a fix for CVE-2026-41100?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-41100 attacked?
- It is attacked with local access, in a network appliance.
- Am I affected by CVE-2026-41100?
- Check whether you run Microsoft 365 Copilot. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A vulnerability classified as improper access control (CWE-284) exists within Microsoft 365 Copilot. The flaw allows an attacker who is already authenticated to the local system to perform spoofing attacks. With a CVSS vector of AV:L/AC:L/PR:L/UI:N, the attack requires local access and low privileges but no user interaction. Successful exploitation allows the attacker to compromise the integrity and confidentiality of the application's operations by masquerading as a legitimate entity. Microsoft has released information regarding this vulnerability via the MSRC Update Guide.
Affected products
- Microsoft Copilot M365 Copilot
Timeline
- 2026-05-12: disclosed
- 2026-05-12: advisory: Microsoft published the security advisory.