CVE-2026-35087 Authentication Bypass in Slican telephone exchanges

Critical 9.3 Published Updated

Attackers can bypass administrative authentication on Slican telephone exchanges to gain unauthorized access and control.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-35087?

CVE-2026-35087 is a critical authentication bypass vulnerability in Slican CCT-1668, published on 27 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

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 - 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.

Weakness: CWE-288

Which versions are affected by CVE-2026-35087?

How do I fix CVE-2026-35087?

No fix has been published for CVE-2026-35087 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-35087 being exploited?

There is no known exploitation of CVE-2026-35087 in the wild and no public exploit code.

Sources

Also known as GHSA-74x7-73gr-c646.

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