CVE-2026-56179

HIGH

Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.

CVSS v3.1 Score

8.3
HIGH
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack Vector
ADJACENT_NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Published: 8/11/2026Modified: 8/13/2026

Related Intelligence (2)

CRITICALZero Day

Patch Tuesday - August 2026

Microsoft is publishing 421 vulnerabilities on August 2026 Patch Tuesday , including 236 vulnerabilities in Windows. This is lower volume than last month’s record-breaking behemoth, but still one of the largest Patch Tuesday totals ever. There is no reason to suppose that Patch Tuesday will ever return to the lower volumes we saw prior to 2026. Microsoft is aware of exploitation in the wild for on

CVE-2026-63520CVE-2026-55040
Rapid7
HIGHVulnerability

NVD HIGH: CVE-2026-56179 — Origin validation error in Windows Network Address Translation (NAT) allows an u...

Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized attacker to perform spoofing over an adjacent network.

CVE-2026-56179
NIST NVD

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56179PatchVendor Advisory