High severity · published Jul 14, 2026
CVE-2026-55145
Outlook Copilot Tampering Vulnerability
7.1
CVSS
0.5%
EPSS
No
On KEV
Description
Improper neutralization of special elements used in a command ('command injection') in Outlook Copilot allows an authorized attacker to perform tampering over a network.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MC
Microsoft Copilot · Microsoft
All versions, or not specified · source: vendor
CO
Copilot · Microsoft
All versions, or not specified · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55145
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-55145
vendor-advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55145
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