CVE-2026-55121

MEDIUM

Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.

CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Attack Vector
LOCAL
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Published: 7/14/2026Modified: 7/15/2026

Related Intelligence (1)

CRITICALZero Day

Patch Tuesday - July 2026

Microsoft is publishing 622 vulnerabilities on July 2026 Patch Tuesday , including a record-breaking 416 Windows vulnerabilities. Microsoft is aware of exploitation in the wild for two of the vulnerabilities published today, both of which are listed on CISA KEV, as well as public disclosure for one other. As usual, browser vulns are not included in the Patch Tuesday count above. Rapid7 noted last

CVE-2026-55040CVE-2026-56164
Rapid7

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55121PatchVendor Advisory