CVE-2026-33247

MEDIUMCVSS 5.3/10EPSS 0.30%

Last modified

CVE-2026-33247 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 0.30% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1
5.3/10

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

EPSS Probability
0.30%

21.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxfoundationNats-Server< 2.11.15
LinuxfoundationNats-Server>= 2.12.0, < 2.12.6

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is 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.
How severe is CVE-2026-33247?
CVE-2026-33247 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.
How do I fix CVE-2026-33247?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-33247?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST