Cyber Resilience

CVE-2026-40621

Critical

Published: 13 May 2026

Published
13 May 2026
Modified
13 May 2026
KEV Added
Patch
CVSS Score v4 9.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0049 38.6th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-40621 is a critical-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Jvn (inferred from references). Its CVSS base score is 9.3 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 38.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

ELECOM wireless LAN access point devices do not require authentication to access some specific URLs. The affected product may be operated without authentication.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1133 External Remote Services Persistence
Adversaries may leverage external-facing remote services to initially access and/or persist within a network.
Why these techniques?

Direct authentication bypass on public-facing management URLs of a network device enables unauthenticated remote access and operation (T1190, T1133).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

Jvn
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

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-288

Authorizing remote access reduces the ability to bypass authentication via unauthorized alternate remote channels.

addresses: CWE-288

Users can identify logons via alternate paths or channels by reviewing the previous logon time.

addresses: CWE-288

Adaptive requirements can apply across access paths, reducing the ability to bypass authentication via alternate channels or paths.

addresses: CWE-288

Centralized IdPs close alternate authentication paths that enable bypass.

addresses: CWE-288

Enforces authentication for non-organizational users, making it harder to bypass via alternate paths or channels.

addresses: CWE-288

Requires authentication to occur exclusively over the isolated trusted path, directly preventing bypass via alternate or untrusted channels.

References