Description (CNA)
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| nats-io / nats-server | affected < 2.11.14; affected >= 2.12.0-RC.1, < 2.12.5 |
CWE
CWE-476
References
- https://github.com/nats-io/nats-server/security/advisories/GHSA-52jh-2xxh-pwh6
- https://github.com/nats-io/nats-server/commit/a1488de6f2ba6e666aef0f9cce0016f7f167d6a8
- https://advisories.nats.io/CVE/secnote-2026-04.txt
ADP enrichment
No English description supplied.
No references supplied.
A flaw was found in NATS-Server. A remote attacker can exploit this vulnerability by connecting to a NATS-Server instance where the 'leafnode' configuration is enabled and compression is active. This pre-authentication flaw allows the attacker to trigger a server crash, resulting in a Denial of Service (DoS) for the affected system.
- https://access.redhat.com/security/cve/CVE-2026-29785
- https://bugzilla.redhat.com/show_bug.cgi?id=2451444
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29785.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