CVE-2026-56181 | Windows Network Address Translation (NAT) Spoofing Vulnerability

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

Published: 2026-07-14 Last update: 2026-07-14 Assigner: [email protected] Source: [email protected]
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-56181 is rated Low Risk (38.6/100): CVSS High severity, with low exploitation likelihood (EPSS 0.24%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-56181

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-07-15 — 0.24% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-56181

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.3 3.1 HIGH
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.6 6.0 [email protected]

Weakness enumeration for CVE-2026-56181

GitHub Security Advisory for CVE-2026-56181

GHSA-q8r6-qhxq-g78g · Severity: high — Origin validation error in Windows Network Address Translation (NAT) allows an unauthorized...

Affected software / configurations for CVE-2026-56181

Vendor Product Version Raw CPE
microsoft windows_server_2025 >= 10.0.26100.0, < 10.0.26100.33158 cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*
microsoft windows_11_25H2 >= 10.0.26200.0, < 10.0.26100.8875 cpe:2.3:o:microsoft:windows_11_25H2:*:*:*:*:*:*:arm64:*
microsoft windows_11_24H2 >= 10.0.26100.0, < 10.0.26100.8875 cpe:2.3:o:microsoft:windows_11_24H2:*:*:*:*:*:*:arm64:*
microsoft windows_11_26H1 >= 10.0.28000.0, < 10.0.28000.2525 cpe:2.3:o:microsoft:windows_11_26H1:*:*:*:*:*:*:x64:*

References for CVE-2026-56181

cvelogic Threat Intelligence