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, 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 Metrics
- Vector
- CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N
- Attack Vector
- network
- Complexity
- high
- Privileges
- low
- User Action
- none
- Scope
- unchanged
- Confidentiality
- low
- Integrity
- low
- Availability
- none
- Weaknesses
- CWE-287CWE-295
Metadata
- Primary Vendor
- LINUXFOUNDATION
- Published
- 3/25/2026
- Last Modified
- 3/26/2026
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
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