CVE-2026-29785

Description

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.

References

https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29785.json

https://github.com/nats-io/nats-server/security/advisories/GHSA-52jh-2xxh-pwh6

https://github.com/nats-io/nats-server/commit/a1488de6f2ba6e666aef0f9cce0016f7f167d6a8

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-15963

https://bugzilla.redhat.com/show_bug.cgi?id=2451444

https://advisories.nats.io/CVE/secnote-2026-04.txt

https://access.redhat.com/security/cve/CVE-2026-29785

https://access.redhat.com/errata/RHSA-2026:23345

https://access.redhat.com/errata/RHSA-2026:22347

https://access.redhat.com/errata/RHSA-2026:21769

Details

Source: Mitre, NVD

Named Vulnerability: GO-2026-4829Named Vulnerability: GHSA-52jh-2xxh-pwh6

Risk Information

CVSS v2

CVSS v3

EPSS