CVE-2026-58253
Description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.
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 — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → 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
Debian Mixed 4 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 2.14.1-1 |
| forky | Fixed | 2.14.1-1 |
| bookworm | Affected | — |
References
- https://security-tracker.debian.org/tracker/CVE-2026-58253
- https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6
- https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6
- https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3
- https://github.com/nats-io/nats-server/releases/tag/v2.11.16
- https://github.com/nats-io/nats-server/releases/tag/v2.12.7
- https://github.com/nats-io/nats-server/releases/tag/v2.14.0
- https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45
CWEs
CWE-287
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.