cvedb.io
CVE-2026-33248
MEDIUM · CVSS 4.2
EPSS exploitation probability: 0%
Published 2026-03-25T21:16:47.563 · Last modified 2026-06-17T10:37:11.377

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, when using mTLS for client identity, with `verify_and_map` to derive a NATS identity from the client certificate's Subject DN, certain patterns of RDN would not be correctly enforced, allowing for authentication bypass. This does require a valid certificate from a CA already trusted for client certificates, and `DN` naming patterns which the NATS maintainers consider highly unlikely. So this is an unlikely attack. Nonetheless, administrators who have been very sophisticated in their `DN` construction patterns might conceivably be impacted. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, developers should review their CA issuing practices.

Affected products

linuxfoundation — nats-server

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.