Bug 2451486 (CVE-2026-33247)

Summary: CVE-2026-33247 github.com/nats-io/nats-server: NATS-Server: Information disclosure of credentials via monitoring port and command-line arguments
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: alcohan, gparvin, jbalunas, pahickey, rhaigner
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in NATS-Server. If the NATS-Server is configured with static credentials provided through command-line arguments (argv) and the monitoring port is enabled, a remote attacker with access to the monitoring port can view these credentials. The /debug/vars endpoint on the monitoring port exposes an unredacted copy of the command-line arguments, leading to information disclosure of sensitive authentication details.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2451501    
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Description OSIDB Bzimport 2026-03-25 21:02:31 UTC
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.