CVE-2026-29785 — NULL Pointer Dereference in Nats-server

CWE-476 — NULL Pointer DereferenceCWE-409 — Improper Handling of Highly Compressed Data (Data Amplification)8 documents6 sources
Severity
7.5HIGHNVD
EPSS
0.1%
top 68.85%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
4
Nats-io Nats-serverLinuxfoundation Nats-serverGithub.com Nats-io Nats-server V2+1 more
Timeline
PublishedMar 25
Latest updateMar 26

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 le…

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitability: 3.9 | Impact: 3.6

Affected Packages5 packages

▶debiandebian/nats-server< nats-server 2.12.6-1 (forky)
▶CVEListV5nats-io/nats-server< 2.11.14+1
▶NVDlinuxfoundation/nats-server2.12.0 — 2.12.5+1
▶Gogithub.com/nats-io_nats-server_v22.12.0-RC.1 — 2.12.5+1
▶Debianlinuxfoundation/nats-server< 2.12.6-1

Patches

Patch: github.com ↗

🔴Vulnerability Details

4
OSV
NATS Server panic via malicious compression on leafnode port in github.com/nats-io/nats-server↗2026-03-26
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OSV
CVE-2026-29785: NATS-Server is a High-Performance server for NATS↗2026-03-25
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OSV
NATS Server panic via malicious compression on leafnode port↗2026-03-24
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GHSA
NATS Server panic via malicious compression on leafnode port↗2026-03-24
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📋Vendor Advisories

2
Red Hat
github.com/nats-io/nats-server: NATS-Server: Denial of Service via leafnode compression↗2026-03-25
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Debian
CVE-2026-29785: nats-server - NATS-Server is a High-Performance server for NATS.io, a cloud and edge native me...↗2026
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🕵️Threat Intelligence

1
Wiz
CVE-2026-29785 Impact, Exploitability, and Mitigation Steps | Wiz↗
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