UBUNTU-CVE-2026-58214
NATS Server versions prior to 2.14.3 and 2.12.12 contain a vulnerability where an authenticated MQTT client can subscribe to the internal $MQTT.deliver.pubrel subject family. This bypasses configured subscribe permissions and exposes MQTT QoS2 protocol metadata for sessions in the account. The issue is fixed in versions 2.14.3 and 2.12.12.
AI Analysis
Technical Summary
NATS Server, a messaging system server, has a vulnerability in versions before 2.14.3 and 2.12.12 that allows an authenticated MQTT client to bypass subscription permissions by subscribing to the internal $MQTT.deliver.pubrel subject family. This exposure reveals MQTT QoS2 protocol metadata related to sessions within the account. The vulnerability does not affect confidentiality beyond metadata exposure, nor does it impact integrity or availability. Fixed versions are 2.14.3 and 2.12.12.
Potential Impact
An authenticated MQTT client can bypass subscription permissions to access internal MQTT QoS2 protocol metadata for sessions in the account. This results in limited confidentiality impact (exposure of protocol metadata) without affecting data integrity or availability.
Mitigation Recommendations
Upgrade NATS Server to version 2.14.3 or later, or 2.12.12 or later, where this vulnerability is fixed. No other mitigations are indicated.
UBUNTU-CVE-2026-58214
Description
NATS Server versions prior to 2.14.3 and 2.12.12 contain a vulnerability where an authenticated MQTT client can subscribe to the internal $MQTT.deliver.pubrel subject family. This bypasses configured subscribe permissions and exposes MQTT QoS2 protocol metadata for sessions in the account. The issue is fixed in versions 2.14.3 and 2.12.12.
CVSS v3.1
Score 4.3medium
Affected software
pkg:deb/ubuntu/[email protected]?arch=source&distro=noblepkg:deb/ubuntu/[email protected]?arch=source&distro=questingpkg:deb/ubuntu/[email protected]~esm1?arch=source&distro=esm-apps/resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
NATS Server, a messaging system server, has a vulnerability in versions before 2.14.3 and 2.12.12 that allows an authenticated MQTT client to bypass subscription permissions by subscribing to the internal $MQTT.deliver.pubrel subject family. This exposure reveals MQTT QoS2 protocol metadata related to sessions within the account. The vulnerability does not affect confidentiality beyond metadata exposure, nor does it impact integrity or availability. Fixed versions are 2.14.3 and 2.12.12.
Potential Impact
An authenticated MQTT client can bypass subscription permissions to access internal MQTT QoS2 protocol metadata for sessions in the account. This results in limited confidentiality impact (exposure of protocol metadata) without affecting data integrity or availability.
Mitigation Recommendations
Upgrade NATS Server to version 2.14.3 or later, or 2.12.12 or later, where this vulnerability is fixed. No other mitigations are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-58214
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:Pro:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 3.1
Threat ID: 6a58b45d68715ace43d6be3a
Added to database: 07/16/2026, 10:37:17 UTC
Last enriched: 07/16/2026, 11:36:14 UTC
Last updated: 07/31/2026, 19:24:47 UTC
Views: 7
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