NN-2026:12-01
Disabled and non-configurable TLS certificate validation in n2os-tui when connecting the Remote Collector to a Guardian or CMC, in Remote Collector before v26.2.0
| Advisory ID | NN-2026:12-01 |
|---|---|
| Topic | Disabled and non-configurable TLS certificate validation in n2os-tui when connecting the Remote Collector to a Guardian or CMC, in Remote Collector before v26.2.0 |
| CWE Impact | CWE-671: Lack of Administrator Control over Security |
| Issue date | 2026-07-07 |
| Affects | Remote Collector < v26.2.0 |
| CVE Name(s) | CVE-2026-31985 |
| CVSS Details | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:L/SI:L/SA:N CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:L |
| CVSS Score | 8.3 (CVSS v4.0) 8.1 (CVSS v3.1) |
| CVE Risk Level | High (CVSS v4.0) High (CVSS v3.1) |
| Risk Level for Nozomi customers | High |
Summary
When the upstream Guardian or CMC was configured in the Remote Collector via n2os-tui, the generated configuration disabled TLS certificate verification, and no option was provided to enable it.
Impact
A malicious actor could perform a man-in-the-middle attack and intercept the communication between the Remote Collector and the Guardian or CMC. This could result in theft of the sync token, impersonation of the server, injection of spoofed data (such as false asset information or vulnerabilities) into the Guardian or CMC, or disruption of the data flow between the Remote Collector and the Guardian or CMC.
Affected Products
Remote Collector < v26.2.0
Workarounds and Mitigations
Manually edit the "n2os.conf.user" file in the Remote Collector and remove the "!" prefix from the upstream Guardian or CMC endpoint entry to enable TLS certificate verification.
Solutions
Upgrade Remote Collector to v26.2.0 or later.
Modification History
Related Links
Acknowledgements
We thank the following parties for their efforts:
- Andrea Palanca of Nozomi Networks Product Security team for finding this issue during an internal investigation
Contact
Nozomi Networks Product Security team can be reached at prodsec@nozominetworks.com.More contact details on the PSIRT page.