CVE-2026-35090
Authentication Bypass in Slican telephone exchanges
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
9.3
Authentication Bypass in Slican telephone exchanges
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.
- Record
CVE-2026-35090- CVSS 4.0
- 9.3 Critical
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 - Weakness
- CWE-288
- Updated
- 2026-11-02
EUVDEUVD-2026-32278
9.3
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.
- Record
EUVD-2026-32278- CVSS 4.0
- 9.3 Critical
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4fcp-hv44-rggc
9.3
In Slican telephone exchanges it is possible to manage the control panel remotely. An...
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.
- Record
GHSA-4fcp-hv44-rggc- CVSS 4.0
- 9.3 Critical
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 - Weakness
- CWE-288
- Updated
- 2026-11-02
NVD
9.3
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.
- Record
CVE-2026-35090- CVSS 4.0
- 9.3 Critical
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 - Weakness
- CWE-288
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-35090 is a critical vulnerability (CVSS 9.3) in Slican Cct-1668, published May 27, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 50th percentile. No source names a fixed version.