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 versions prior to 2.14.1 and 2.12.9 contain a vulnerability where an MQTT client can inject protocol control characters into subscription filters. These characters are forwarded as NATS protocol data to route or leafnode connections, corrupting the protocol stream and enabling injection of unintended NATS protocol operations. This vulnerability is identified as CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The issue is fixed in versions 2.14.1 and 2.12.9.
AI Analysis
Technical Summary
The vulnerability in nats-io nats-server allows an MQTT client to include special protocol control characters in subscription filters. These characters are forwarded downstream as NATS protocol data to route or leafnode connections, which corrupts the protocol stream and permits injection of unintended NATS protocol operations. This improper neutralization of special elements corresponds to CWE-74. The flaw affects versions prior to 2.14.1 and 2.12.9 and has a CVSS v3.1 score of 7.1, indicating high severity. The vulnerability is resolved in nats-server versions 2.14.1 and 2.12.9.
Potential Impact
Successful exploitation allows an attacker controlling an MQTT client to inject unintended NATS protocol operations by corrupting the forwarded protocol stream. This can lead to unauthorized protocol manipulation with high confidentiality impact and low integrity impact, but no availability impact as per the CVSS vector. The vulnerability could compromise the integrity of the messaging system's protocol communication.
Mitigation Recommendations
A fix is available in nats-server versions 2.14.1 and 2.12.9. Users should upgrade to at least one of these versions to remediate the vulnerability. No additional mitigation guidance is provided or required beyond applying the official fix.
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 versions prior to 2.14.1 and 2.12.9 contain a vulnerability where an MQTT client can inject protocol control characters into subscription filters. These characters are forwarded as NATS protocol data to route or leafnode connections, corrupting the protocol stream and enabling injection of unintended NATS protocol operations. This vulnerability is identified as CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component). The 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
The vulnerability in nats-io nats-server allows an MQTT client to include special protocol control characters in subscription filters. These characters are forwarded downstream as NATS protocol data to route or leafnode connections, which corrupts the protocol stream and permits injection of unintended NATS protocol operations. This improper neutralization of special elements corresponds to CWE-74. The flaw affects versions prior to 2.14.1 and 2.12.9 and has a CVSS v3.1 score of 7.1, indicating high severity. The vulnerability is resolved in nats-server versions 2.14.1 and 2.12.9.
Potential Impact
Successful exploitation allows an attacker controlling an MQTT client to inject unintended NATS protocol operations by corrupting the forwarded protocol stream. This can lead to unauthorized protocol manipulation with high confidentiality impact and low integrity impact, but no availability impact as per the CVSS vector. The vulnerability could compromise the integrity of the messaging system's protocol communication.
Mitigation Recommendations
A fix is available in nats-server versions 2.14.1 and 2.12.9. Users should upgrade to at least one of these versions to remediate the vulnerability. No additional mitigation guidance is provided or required beyond applying the official fix.
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: 07/08/2026, 20:28:28 UTC
Last updated: 07/08/2026, 20:28:28 UTC
Views: 2
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