Medium 4.2Published Mar 25, 2026

CVE-2026-33248NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system.

Updated under an hour ago (2026-10-19 06:10 UTC)

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Every CVE for linuxfoundation nats-server

Exploited in the last 30 days

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.

CVSS: 4.2 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness (CWE): CWE-287, CWE-295
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

linuxfoundation nats-server linuxfoundation:nats-server	before 2.11.15; from 2.12.0 before 2.12.6	NVD

References

https://advisories.nats.io/CVE/secnote-2026-13.txtvendor-advisory
https://github.com/nats-io/nats-server/security/advisories/GHSA-3f24-pcvm-5jqcvendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.