CVE-2026-33249
Description
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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or โ if you've already worked around this in production โ publish your fix to the community-verified tier.
โ Propose a mitigation on Community โ Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | fixed | 0 |
| debian | forky | fixed | 2.12.6-1 |
| debian | sid | fixed | 2.12.6-1 |
| debian | trixie | fixed | 0 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Go | github.com/nats-io/nats-server/v2 | >=2.11.0,<2.11.15 | 2.11.15 |
| Go | github.com/nats-io/nats-server/v2 | >=2.12.0-preview.1,<2.12.6 | 2.12.6 |
| Go | github.com/nats-io/nats-server | | |
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-8m2x-3m6q-6w8j
- https://nvd.nist.gov/vuln/detail/CVE-2026-33249
- https://advisories.nats.io/CVE/secnote-2026-15.txt
- https://github.com/nats-io/nats-server
- https://www.suse.com/security/cve/CVE-2026-33249.html
- https://security-tracker.debian.org/tracker/CVE-2026-33249
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.