NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-58210
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-08 20:16:53 UTC
Updated2026-07-13 15:14:12 UTC
DescriptionNATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the parser waited for the advertised MQTT packet length. This issue is fixed in versions 2.14.3 and 2.12.12.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.007320000 probability, percentile 0.500710000 (date 2026-07-13)

Problem Types: CWE-400 | CWE-400 CWE-400: Uncontrolled Resource Consumption

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Linuxfoundation Nats-server All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Nats-io Nats-server affected < 2.12.12 Not specified
CNA Nats-io Nats-server affected >= 2.14.0-RC.1, < 2.14.3 Not specified

References

ReferenceSourceLinkTags
github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862a... [email protected] github.com Patch
github.com/nats-io/nats-server/releases/tag/v2.12.12 [email protected] github.com Release Notes
github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qg [email protected] github.com Vendor Advisory
github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7ed... [email protected] github.com Patch
github.com/nats-io/nats-server/releases/tag/v2.14.3 [email protected] github.com Release Notes
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