Cyber Resilience

CVE-2026-35087

Critical

Published: 27 May 2026

Published
27 May 2026
Modified
27 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 0.0066 47.1th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-35087 is a critical-severity Authentication Bypass Using an Alternate Path or Channel (CWE-288) vulnerability in Cert (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 47.1th 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

Slican telephone exchanges allow administrative protocol authentication bypass. An attacker can bypass the need to enter login credentials by executing the appropriate command. This issue was fixed in versions below: - NCP: version 1.24.0250 - IPx series: version 6.61.0040 -…

more

CCT-1668: version 6.56.0430 - MAC-6400: version 6.56.0430 - CXS-0424: version 6.30.0510 The issue STILL EXISTS in End-Of-Life telephone exchanges in versions 4.xx and below: - CCT-1668 (CCT1CPU) - MAC-6400 - CXS-0424 These products were discontinued in 2011 and 2012 and and will not receive updates. These products require a hardware update in order to receive a software update. The vendor recommends that users of these devices contact the their service department directly to determine the options for upgrading.

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.
Why these techniques?

Authentication bypass on administrative protocol of network-accessible telephone exchange directly enables remote exploitation of a public-facing service.

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

Affected Assets

Cert
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