CVE-2026-33247

NATS credentials are exposed in monitoring port via command-line argv

MEDIUM
5.3
CVSS Score
Published: March 25, 2026 at 08:02 PM UTC
Updated: September 9, 2026 at 01:19 PM UTC
2 products affected across 2 vendorsNats ServerNats Server

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.11.152.12.0 ≤ v < 2.12.6
Affected range stops below 2.11.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.12.6, so it looks safe — our inference, not a vendor statement
v < 2.11.15v < 2.12.6
Affected range stops below 2.11.15, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.12.6, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (8)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/nats-io/nats-server/security/advisories/GHSA-x6g4-f6q3-fqvv
x_refsource_MISCMitigationVendor Advisory
Source: cverecord
https://advisories.nats.io/CVE/secnote-2026-14.txt
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:21769
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:22347
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/errata/RHSA-2026:23345
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://access.redhat.com/security/cve/CVE-2026-33247
Source: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
https://bugzilla.redhat.com/show_bug.cgi?id=2451486

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
NONE
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-215CWE-214

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