Cyber Posture

CVE-2026-36539

High

Published: 27 May 2026

Published
27 May 2026
Modified
28 May 2026
KEV Added
Patch
CVSS Score 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0002 6.5th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-36539 is a high-severity Exposure of Sensitive Information to an Unauthorized Actor (CWE-200) vulnerability. Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Unsecured Credentials (T1552); ranked at the 6.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Unsecured Credentials (T1552) and 3 other techniques.
Threat & Defense Details

Likely Mitigating ControlsAI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-200

Automated marking applies security attributes to system outputs, making it harder for attackers to exploit unmarked sensitive information leading to unauthorized exposure.

addresses: CWE-200

Proper attribute retention and permitted-value enforcement limits unauthorized actors from accessing sensitive information lacking correct labels.

addresses: CWE-200

Prevents unauthorized exposure of sensitive information by prohibiting untrusted external systems from processing or storing it.

addresses: CWE-200

By enforcing authorization matching prior to sharing, the control reduces the risk of exposing sensitive information to unauthorized actors.

addresses: CWE-200

Review and removal of nonpublic information from publicly accessible systems directly prevents exposure of sensitive data to unauthorized actors.

addresses: CWE-200

Data mining protection mechanisms detect and block unauthorized bulk extraction of sensitive data, directly mitigating exposure to unauthorized actors.

addresses: CWE-200

Literacy training teaches users to recognize and avoid actions that result in unauthorized exposure of sensitive information.

addresses: CWE-200

Retaining and monitoring training records confirms personnel have completed privacy and security awareness training on handling sensitive data, reducing the chance of unauthorized exposure due to lack of knowledge.

MITRE ATT&CK Enterprise TechniquesAI

T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
T1087 Account Discovery Discovery
Adversaries may attempt to get a listing of valid accounts, usernames, or email addresses on a system or within a compromised environment.
T1018 Remote System Discovery Discovery
Adversaries may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for Lateral Movement from the current system.
T1016 System Network Configuration Discovery Discovery
Adversaries may look for details about the network configuration and settings, such as IP and/or MAC addresses, of systems they access or through information discovery of remote systems.
Why these techniques?

Unauthenticated CGI endpoint directly exposes admin/WiFi/PPPoE credentials (T1552) plus account and device inventory (T1087/T1018/T1016).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Netis AC1200 Router NC21 V4.0.1.4296 exposes a CGI endpoint /cgi-bin/skk_get.cgi that returns the entire router configuration as a JSON response with no authentication required. Any attacker on the LAN can send a single HTTP GET request and instantly retrieve administrator…

more

credentials, WiFi passwords, PPPoE credentials, DDNS credentials, and a full map of all connected devices.

Deeper analysisAI

Automated synthesis unavailable for this CVE.

Details

CWE(s)
OWASP Top 10 Web 2025

References