RCE in Microsoft Outlook For iOS

CVE-2026-42893

Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to perform tampering over a network.

Vulnerability class: Command Injection (OS Command Injection)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.007 (51.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-42893: held from 0.004 to 0.007.

EPSS over last 30 days · oldest: 0.004 · newest: 0.007 · change: +0.003

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42893?
CVE-2026-42893 is a high-severity vulnerability in Microsoft Outlook For iOS, classified under Command Injection. CVSS score: 7.4/10. Published 2026-05-12.
How severe is CVE-2026-42893?
High severity. CVSS v3 base score is 7.4 out of 10.