CVE-2026-26164

HIGH

Improper neutralization of special elements in output used by a downstream component ('injection') in M365 Copilot allows an unauthorized attacker to disclose information over a network.

CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Published: 5/7/2026Modified: 5/8/2026

Related Intelligence (2)

CRITICALAi

Patch Tuesday - May 2026

Microsoft is publishing 137 vulnerabilities on May 2026 Patch Tuesday . Microsoft is not aware of exploitation in the wild or public disclosure for any of these vulnerabilities. So far this month, Microsoft has provided patches to address 133 browser vulnerabilities, which are not included in the Patch Tuesday count above. Windows Netlogon: critical RCE Anyone responsible for securing a domain con

CVE-2026-41089CVE-2020-1472
Rapid7
HIGHVulnerability

NVD HIGH: CVE-2026-26164 — Improper neutralization of special elements in output used by a downstream compo...

Improper neutralization of special elements in output used by a downstream component ('injection') in M365 Copilot allows an unauthorized attacker to disclose information over a network.

CVE-2026-26164
NIST NVD

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26164Vendor Advisory