Description (CNA)
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, a client which can connect to the leafnode port can crash the nats-server with a certain malformed message pre-authentication. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable leafnode support if not needed or restrict network connections to the leafnode port, if plausible without compromising the service offered.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| nats-io / nats-server | affected < < 2.11.15; affected >= 2.12.0-RC.1, < 2.12.6 |
CWE
CWE-20
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-vprv-35vv-q339
- https://advisories.nats.io/CVE/secnote-2026-10.txt
ADP enrichment
No English description supplied.
No references supplied.
A flaw was found in NATS-Server, a high-performance messaging system. A remote attacker, by connecting to the leafnode port and sending a specially crafted malformed message before authentication, can cause the nats-server to crash. This vulnerability leads to a Denial of Service (DoS), making the server unavailable to legitimate users.
- https://access.redhat.com/security/cve/CVE-2026-33218
- https://bugzilla.redhat.com/show_bug.cgi?id=2451450
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33218.json
- https://access.redhat.com/errata/RHSA-2026:22347
- https://access.redhat.com/errata/RHSA-2026:23345
- https://access.redhat.com/errata/RHSA-2026:21769