CVE-2026-33249
NATS: Message tracing can be redirected to arbitrary subject
CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
7th
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Starting in version 2.11.0 and prior to versions 2.11.15 and 2.12.6, a valid client which uses message tracing headers can indicate that the trace messages can be sent to an arbitrary valid subject, including those to which the client does not have publish permission. The payload is a valid trace message and not chosen by the attacker. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.
| CWE | CWE-863 |
| Vendor | nats-io |
| Product | nats-server |
| Published | Mar 25, 2026 |
| Last Updated | Mar 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
None
Affected Versions
nats-io / nats-server
>= 2.11.0, < 2.11.15 >= 2.12.0-preview.1, < 2.12.6