CVE-2026-54121

HIGH

Improper authorization in Active Directory Certificate Services (AD CS) allows an authorized attacker to elevate privileges over a network.

CVSS v3.1 Score

8.8
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Published: 7/14/2026Modified: 7/21/2026

Related Intelligence (2)

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Earlier this month Microsoft warned that, because the latest AI models can now help discover vulnerabilities, CSOs will see a higher volume of security updates every month. It wasn’t kidding. Today the company issued a record number of patches , with 59 rated as critical. And Microsoft is now recommending that customers accelerate their patching schedules to more quickly deal with critical flaws.

CVE-2026-56155CVE-2026-56164
CSO Online
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-2026-54121PatchVendor Advisory