CVE-2026-78523

MEDIUM

Use after free in Windows DNS allows an unauthorized attacker to deny service over a network.

CVSS v3.1 Score

5.9
MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Published: 9/8/2026Modified: 9/10/2026

Related Intelligence (2)

CRITICALRansomware

Patch Tuesday - September 2026

Microsoft is publishing 974 own-product vulnerabilities on September 2026 Patch Tuesday , including 723 vulnerabilities in Windows. Along with Microsoft fixes for 25 non-Microsoft CVEs, that brings the total number of vulnerabilities on the table today to 999. Whether this is the biggest Patch Tuesday ever depends on how we count, but this is by far the most CVEs that Microsoft has ever published

CVE-2026-85880CVE-2026-81963
Rapid7
HIGHVulnerability

NVD HIGH: CVE-2026-78523 — Use after free in Windows DNS allows an unauthorized attacker to deny service ov...

Use after free in Windows DNS allows an unauthorized attacker to deny service over a network.

CVE-2026-78523
NIST NVD

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-78523PatchVendor Advisory