CVE-2026-33247

Summary

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 Software

Weaknesses

• CWE-215: CWE-215: Insertion of Sensitive Information Into Debugging Code

ADP Enrichment

CISA ADP Vulnrichment

• SSVC:
• Exploitation: none
  • Automatable: no
  • Technical Impact: total

github.com/nats-io/nats-server: NATS-Server: Information disclosure of credentials via monitoring port and command-line arguments

Additional References

• 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
• https://access.redhat.com/errata/RHSA-2026:22347
• https://access.redhat.com/errata/RHSA-2026:21769
• https://access.redhat.com/errata/RHSA-2026:23345

References

• https://github.com/nats-io/nats-server/security/advisories/GHSA-x6g4-f6q3-fqvv
• https://advisories.nats.io/CVE/secnote-2026-14.txt

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