CVE-2026-58213: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') in nats-io nats-server
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.1 and 2.12.9, an MQTT client could include protocol control characters in subscription filters that were later forwarded as NATS protocol data to route or leafnode connections, corrupting the forwarded protocol stream and allowing injection of unintended NATS protocol operations. This issue is fixed in versions 2.14.1 and 2.12.9.
AI Analysis
Technical Summary
CVE-2026-58213 is an injection vulnerability (CWE-74) in nats-io nats-server. Specifically, MQTT clients could include special protocol control characters in subscription filters that are forwarded downstream as NATS protocol data. This corrupts the protocol stream and allows injection of unintended NATS protocol operations on route or leafnode connections. The issue affects versions prior to 2.14.1 and 2.12.9 and is fixed in those versions.
Potential Impact
Successful exploitation could allow an attacker with MQTT client privileges to inject unintended NATS protocol operations, potentially disrupting or manipulating message routing between NATS servers. The CVSS score of 7.1 indicates high severity with high confidentiality impact, low integrity impact, and no availability impact.
Mitigation Recommendations
A fix is available in nats-server versions 2.14.1 and 2.12.9. Users should upgrade to these versions or later to remediate this vulnerability. No additional vendor advisory details are provided, so patching is the primary mitigation.
CVE-2026-58213: CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection') in nats-io nats-server
Description
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.1 and 2.12.9, an MQTT client could include protocol control characters in subscription filters that were later forwarded as NATS protocol data to route or leafnode connections, corrupting the forwarded protocol stream and allowing injection of unintended NATS protocol operations. This issue is fixed in versions 2.14.1 and 2.12.9.
CVSS v3.1
Score 7.1high
Affected software
pkg:github/nats-io/nats-serverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-58213 is an injection vulnerability (CWE-74) in nats-io nats-server. Specifically, MQTT clients could include special protocol control characters in subscription filters that are forwarded downstream as NATS protocol data. This corrupts the protocol stream and allows injection of unintended NATS protocol operations on route or leafnode connections. The issue affects versions prior to 2.14.1 and 2.12.9 and is fixed in those versions.
Potential Impact
Successful exploitation could allow an attacker with MQTT client privileges to inject unintended NATS protocol operations, potentially disrupting or manipulating message routing between NATS servers. The CVSS score of 7.1 indicates high severity with high confidentiality impact, low integrity impact, and no availability impact.
Mitigation Recommendations
A fix is available in nats-server versions 2.14.1 and 2.12.9. Users should upgrade to these versions or later to remediate this vulnerability. No additional vendor advisory details are provided, so patching is the primary mitigation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-29T17:09:25.873Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4eafe7c9d9e3dbe3adea24
Added to database: 07/08/2026, 20:15:35 UTC
Last enriched: 07/16/2026, 10:12:41 UTC
Last updated: 08/22/2026, 10:52:10 UTC
Views: 81
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