High severity · published May 12, 2026
CVE-2026-42893
Microsoft Outlook for iOS Tampering Vulnerability
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
Improper neutralization of special elements used in a command ('command injection') in M365 Copilot allows an unauthorized attacker to perform tampering over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OU
Outlook · Microsoft
before 5.2617.1 · source: NVD
MO
Microsoft Outlook for iOS · Microsoft
1.0.0 before 5.2617.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42893
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42893
Vendor Advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42893
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