GHSA-52jh-2xxh-pwh6

Source

https://github.com/advisories/GHSA-52jh-2xxh-pwh6

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-52jh-2xxh-pwh6/GHSA-52jh-2xxh-pwh6.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-52jh-2xxh-pwh6

Aliases

CVE-2026-29785

Downstream

MINI-c4j2-g8fj-j3cv

MINI-gf42-rfj7-mw5m

Related

CGA-h2h5-63c6-272r

Published

2026-03-24T21:29:06Z

Modified

2026-03-25T19:59:16.170400Z

Severity

7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator

Summary

NATS Server panic via malicious compression on leafnode port

Details

Background

NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing.

When configured to accept leafnode connections (for a hub/spoke topology of multiple nats-servers), then the default configuration allows for negotiating compression; a malicious remote NATS server can trigger a server panic via that compression.

Problem Description

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).

Context: a NATS server can form various clustering topologies, including local clusters, and superclusters of clusters, but leafnodes allow for separate administrative domains to link together with limited data communication; eg, a server in a moving vehicle might use a local leafnode for agents to connect to, and sync up to a central service as and when available. The leafnode configuration here is where the central server allows other NATS servers to connect into it, almost like regular NATS clients. Documentation examples typically use port 7422 for leafnode communications.

Affected Versions

Version 2, prior to v2.11.14 or v2.12.5

Workarounds

Disable compression on the leafnode port:

leafnodes {
  port: 7422
  compression: off
}

Database specific

{
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-24T21:29:06Z",
    "cwe_ids": [
        "CWE-476"
    ],
    "nvd_published_at": null,
    "severity": "HIGH"
}

References

Affected packages

Go / github.com/nats-io/nats-server/v2

Package

Name: github.com/nats-io/nats-server/v2; View open source insights on deps.dev
Purl: pkg:golang/github.com/nats-io/nats-server/v2

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

2.11.14

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-52jh-2xxh-pwh6/GHSA-52jh-2xxh-pwh6.json"

Go / github.com/nats-io/nats-server/v2

Package

Name: github.com/nats-io/nats-server/v2; View open source insights on deps.dev
Purl: pkg:golang/github.com/nats-io/nats-server/v2

Affected ranges

Type: SEMVER
Events: Introduced

2.12.0-RC.1

Fixed

2.12.5

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/03/GHSA-52jh-2xxh-pwh6/GHSA-52jh-2xxh-pwh6.json"