CVE-2026-35087: Slican Telephone Exchanges authentication bypass in administrative protocol

CVE-2026-35087 · Severity: info · CVSS 9.3 · Published 2026-05-27

Slican telephone exchanges, which manage corporate voice communications and PBX services, contain a flaw that allows unauthorized individuals to bypass administrative login requirements. By sending a specific command, an attacker can gain full control over the device without needing a password. This could lead to eavesdropping on calls, service disruptions, or unauthorized changes to the organization's telephony infrastructure.

Technologies: Slican CCT-1668, Slican CXS-0424, Slican MAC-6400. Vendors: Slican.

Quick answers

Is CVE-2026-35087 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-35087 being exploited in the wild.
How severe is CVE-2026-35087?
Informational severity, with a CVSS score of 9.3, published 27 May 2026.
Which products and versions are affected?
Slican CCT-1668 below 6.56.0430; 4.xx and below (EOL); Slican CXS-0424 below 6.30.0510; 4.xx and below (EOL); Slican IPx series below 6.61.0040; Slican MAC-6400 below 6.56.0430; 4.xx and below (EOL); and 1 more.
Is there a fix for CVE-2026-35087?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-35087 attacked?
It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-35087?
Check whether you run Slican CCT-1668, Slican CXS-0424, Slican IPx series or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A vulnerability classified as CWE-288 (Authentication Bypass Using an Alternate Path or Channel) exists in the administrative protocol of several Slican telephone exchange models. The flaw allows a remote, unauthenticated attacker to bypass the authentication mechanism entirely by executing a specific command within the administrative protocol. Successful exploitation grants the attacker full administrative access to the device. While patches are available for modern firmware branches, several legacy models (CCT-1668, MAC-6400, CXS-0424) running version 4.xx or lower are end-of-life and require hardware upgrades to receive security fixes.

Affected products

  • Slican NCP below 1.24.0250
  • Slican IPx series below 6.61.0040
  • Slican CCT-1668 below 6.56.0430; 4.xx and below (EOL)
  • Slican MAC-6400 below 6.56.0430; 4.xx and below (EOL)
  • Slican CXS-0424 below 6.30.0510; 4.xx and below (EOL)

Timeline

  • 2026-05-27: advisory: Initial disclosure by CERT.PL

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.