Linuxfoundation Nats-Server
CVE-2026-33247
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.
What this means for your business
- It affects Linuxfoundation Nats-Server. It matters if your company, or a supplier that handles your data, runs it.
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.4% chance of attack attempts being seen in the next 30 days, ranking above 35% of all known flaws.
What to do
- 1Check whether your company or your suppliers run Linuxfoundation Nats-Server, and which version. The affected versions are listed further down this page.
- 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.
Not sure if your company is exposed?
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Scoring
- CVSS
- 7.4 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N- Weakness
- CWE-215
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-03-25
- Last modified
- 2026-09-09
- Sources
- NVD
Affected products
- Linuxfoundation Nats-Server- 2.11.15, 2.12.0 - 2.12.6
As listed in the NVD configuration data. Not a statement about your estate.
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