CVE-2026-35090 Authentication Bypass in Slican telephone exchanges
Unauthenticated attackers can bypass admin authentication via caller ID to gain full control of Slican telephone exchanges.
- 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-2026-35090?
CVE-2026-35090 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
In Slican telephone exchanges it is possible to manage the control panel remotely. An unauthenticated attacker can connect to the modem via a telephone with a specific caller ID. This allows them to bypass admin authentication and gain full access to the service protocol and configuration panel. This vulnerability is independent of the telephone exchanges configuration. If remote access is disabled, calling with this caller ID will temporarily enable it.
This issue was fixed in versions below: - IPL-256: version 6.61.0040 - IPM-032: 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-2026-35090?
How do I fix CVE-2026-35090?
No fix has been published for CVE-2026-35090 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-2026-35090 being exploited?
There is no known exploitation of CVE-2026-35090 in the wild and no public exploit code.
Sources
Also known as GHSA-4fcp-hv44-rggc.