NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, if a nats-server is run with static credentials for all clients provided via argv (the command-line), then those credentials are visible to any user who can see the monitoring port, if that too is enabled. The /debug/vars end-point contains an unredacted copy of argv. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, configure credentials inside a configuration file instead of via argv, and do not enable the monitoring port if using secrets in argv. Best practice remains to not expose the monitoring port to the Internet, or to untrusted network sources.
Weakness
The product inserts sensitive information into debugging code, which could expose this information if the debugging code is not disabled in production.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nats-server | Linuxfoundation | * | 2.11.15 (excluding) |
| Nats-server | Linuxfoundation | 2.12.0 (including) | 2.12.6 (excluding) |
| Multicluster Global Hub 1.4.5 | RedHat | multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1779579439 | * |
| Multicluster Global Hub 1.5.4 | RedHat | multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1778867753 | * |
| Multicluster Global Hub 1.6.2 | RedHat | multicluster-globalhub/multicluster-globalhub-grafana-rhel9:1780167118 | * |
| Nats-server | Ubuntu | questing | * |
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
References
- https://advisories.nats.io/CVE/secnote-2026-14.txt
- https://github.com/nats-io/nats-server/security/advisories/GHSA-x6g4-f6q3-fqvv
- https://access.redhat.com/errata/RHSA-2026:21769
- https://access.redhat.com/errata/RHSA-2026:22347
- https://access.redhat.com/errata/RHSA-2026:23345
- https://access.redhat.com/security/cve/CVE-2026-33247
- https://bugzilla.redhat.com/show_bug.cgi?id=2451486
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33247.json