Cyber Resilience

CVE-2026-42893

HighRCE

Published: 12 May 2026

Published
12 May 2026
Modified
13 May 2026
KEV Added
—
Patch
—
CVSS Score v3.1 7.4 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N
EPSS Score 0.0005 17.1th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-42893 is a high-severity Command Injection (CWE-77) vulnerability in Microsoft Outlook. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 17.1th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as Enterprise AI Assistants; in the Other ATLAS/OWASP Terms risk domain.

EU & UK References

Vulnerability details

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

CWE(s)
CWE-77

AI Security AnalysisAI

AI Category
Enterprise AI Assistants
Risk Domain
Other ATLAS/OWASP Terms
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: m365 copilot

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
Why these techniques?

Command injection in a network-exposed M365 service directly enables exploitation of public-facing apps (T1190) and arbitrary command execution (T1059).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2026-21520Same vendor: Microsoft
CVE-2026-26133Same product: Microsoft Outlook
CVE-2025-59272Same vendor: Microsoft
CVE-2025-59286Same vendor: Microsoft
CVE-2025-59252Same vendor: Microsoft
CVE-2026-21518Same vendor: Microsoft
CVE-2026-21516Same vendor: Microsoft
CVE-2026-21257Same vendor: Microsoft
CVE-2026-33111Same vendor: Microsoft
CVE-2025-53787Same vendor: Microsoft

Affected Assets

microsoft
outlook
≤ 5.2617.1

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References