CVE-2026-29785
NATS Server panic via malicious compression on leafnode port
- State
- Published
- Severity
- 7.5 High
- Published
- Mar 25, 2026
- Updated
- Sep 9, 2026
- Reserved
- Mar 4, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | GitHub_M |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
nats-servernats-io |
|
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
- https://access.redhat.com/security/cve/CVE-2026-29785vdb-entry
- RHBZ#2451444issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-29785.json
- https://access.redhat.com/errata/RHSA-2026:22347vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:23345vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:21769vendor-advisory
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