CVE-2026-58254 NATS Server: Incomplete fix for CVE-2026-33249: Leaf node connections bypass Nats-Trace-Dest permission check
Leafnode operators can bypass trace destination permissions to send unauthorized trace events and disrupt message delivery or storage.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-58254?
CVE-2026-58254 is a medium-severity missing authorization vulnerability in nats-io nats-server, published on 8 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.8, message trace destination checks were applied to ordinary client connections but not consistently to messages arriving through leafnode connections, allowing a leafnode operator to send trace events to subjects that would not otherwise be permitted and to use trace-only behavior to prevent normal delivery or storage of affected messages. This issue is fixed in versions 2.14.3 and 2.12.8.
Weakness: CWE-863
Which versions are affected by CVE-2026-58254?
1 open source package ship an affected version, including nats. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
nats Bitnami | All versions | 2.12.8, 2.14.3 |
Products include Linuxfoundation Nats-Server.
How do I fix CVE-2026-58254?
Upgrade nats to a fixed version for your release line: 2.12.8 or 2.14.3.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-58254 being exploited?
There is no known exploitation of CVE-2026-58254 in the wild and no public exploit code.
Other vulnerabilities in nats-io nats-server
- CVE-2022-28357 NATS nats-server allows directory traversal via unintended path to a management action
- CVE-2026-58253 NATS Server: Route API Auth Bypass
- CVE-2022-24450 Incorrect Authorization in NATS nats-server
- CVE-2026-33216 NATS has MQTT plaintext password disclosure
- CVE-2026-58207 NATS Server: Remote crash via integer overflow in Connz pagination
Sources
Also known as BIT-nats-2026-58254, DEBIAN-CVE-2026-58254, GHSA-p3j5-5hrq-p75h, JLSEC-2026-1154, MINI-65v7-hwpp-fw54, MINI-jx7f-g3fv-3hwg and 1 more.