Is CVE-2026-42893 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-42893 being exploited in the wild.

How severe is CVE-2026-42893?

High severity, with a CVSS score of 7.4, published 12 May 2026.

Which products and versions are affected?

Microsoft M365 Copilot Versions prior to May 2026 updates; Microsoft Outlook for iOS versions up to (excluding) 5.2617.1.

Is there a fix for CVE-2026-42893?

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-2026-42893 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-42893?

Check whether you run Microsoft M365 Copilot, Microsoft Outlook or Microsoft Outlook for iOS at an affected version. 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.

CVE-2026-42893: Microsoft M365 Copilot command injection

CVE-2026-42893 · Severity: high · CVSS 7.4 · Published 2026-05-12

Microsoft M365 Copilot, an AI-powered productivity tool integrated into Microsoft 365 apps, is vulnerable to a command injection flaw. An unauthorized attacker could exploit this over the network to tamper with data or system integrity. This could lead to unauthorized changes in documents, emails, or other corporate data managed by the AI assistant.

Technologies: Microsoft M365 Copilot, Microsoft Outlook. Vendors: Microsoft.

Quick answers

Is CVE-2026-42893 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-42893 being exploited in the wild.
How severe is CVE-2026-42893?: High severity, with a CVSS score of 7.4, published 12 May 2026.
Which products and versions are affected?: Microsoft M365 Copilot Versions prior to May 2026 updates; Microsoft Outlook for iOS versions up to (excluding) 5.2617.1.
Is there a fix for CVE-2026-42893?: 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-2026-42893 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-42893?: Check whether you run Microsoft M365 Copilot, Microsoft Outlook or Microsoft Outlook for iOS at an affected version. 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 command injection vulnerability (CWE-77) exists in Microsoft M365 Copilot due to improper neutralization of special elements used in a command. The vulnerability can be exploited by an unauthenticated attacker over a network, though Microsoft's assessment suggests user interaction may be required (UI:R) and the impact is primarily on system integrity (tampering). Successful exploitation allows the attacker to execute unauthorized commands within the context of the Copilot environment. Affected components include Outlook for iOS versions prior to 5.2617.1. Microsoft has released security updates to address this issue.

Affected products

Microsoft M365 Copilot Versions prior to May 2026 updates
Microsoft Outlook for iOS versions up to (excluding) 5.2617.1

Timeline

2026-05-12: disclosed
2026-05-12: advisory: Microsoft released the security update guide for this vulnerability.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42893

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