CVE-2026-29785

NATS Server panic via malicious compression on leafnode port

Published Mar 25, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-52jh-2xxh-pwh6 NATS Server panic via malicious compression on leafnode port
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Linuxfoundation
Linuxfoundation nats-server
CPEs cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*
Vendors & Products Linuxfoundation
Linuxfoundation nats-server
Type Values Removed Values Added
First Time appeared Nats
Nats nats Server
Vendors & Products Nats
Nats nats Server
Type Values Removed Values Added
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.
Title NATS Server panic via malicious compression on leafnode port
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 9, 2026, 12:04 PM
Reserved
Mar 4, 2026, 4:26 PM
Status
Modified
Published
Mar 25, 2026, 8:16 PM
Modified
Sep 9, 2026, 1:19 PM
Severity
Important
Public date
Mar 25, 2026, 7:38 PM