CVE-2026-58252: CWE-285: Improper Authorization in nats-io nats-server
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, an authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset of it, and queue subscriptions could also affect delivery to legitimate queue consumers. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.
AI Analysis
Technical Summary
CVE-2026-58252 describes an improper authorization vulnerability (CWE-285) in nats-io nats-server. Before fixed versions 2.14.0, 2.12.7, and 2.11.16, an authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset of it. Additionally, queue subscriptions could impact delivery to legitimate queue consumers. This vulnerability allows unauthorized message reception despite access controls. The issue is fixed in the specified versions.
Potential Impact
The vulnerability allows an authenticated user to bypass subject-level deny rules under certain wildcard subscription configurations, potentially leading to unauthorized access to message data. There is no impact on integrity or availability reported. The CVSS score of 6.5 (medium severity) reflects a network attack vector with low complexity and no user interaction required, resulting in high confidentiality impact but no integrity or availability impact.
Mitigation Recommendations
Upgrade nats-server to version 2.14.0, 2.12.7, or 2.11.16 or later, where this improper authorization vulnerability is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed fixed in these versions.
CVE-2026-58252: CWE-285: Improper Authorization 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 2.14.0, 2.12.7, and 2.11.16, an authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset of it, and queue subscriptions could also affect delivery to legitimate queue consumers. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.
CVSS v3.1
Score 6.5medium
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-2026-58252 describes an improper authorization vulnerability (CWE-285) in nats-io nats-server. Before fixed versions 2.14.0, 2.12.7, and 2.11.16, an authenticated user could receive messages on denied subjects when a wildcard subscription overlapped with a configured wildcard deny rule but was not a subset of it. Additionally, queue subscriptions could impact delivery to legitimate queue consumers. This vulnerability allows unauthorized message reception despite access controls. The issue is fixed in the specified versions.
Potential Impact
The vulnerability allows an authenticated user to bypass subject-level deny rules under certain wildcard subscription configurations, potentially leading to unauthorized access to message data. There is no impact on integrity or availability reported. The CVSS score of 6.5 (medium severity) reflects a network attack vector with low complexity and no user interaction required, resulting in high confidentiality impact but no integrity or availability impact.
Mitigation Recommendations
Upgrade nats-server to version 2.14.0, 2.12.7, or 2.11.16 or later, where this improper authorization vulnerability is fixed. No other mitigation or temporary workaround is indicated. Patch status is confirmed fixed in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-29T21:54:30.330Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4eafe7c9d9e3dbe3adea3c
Added to database: 07/08/2026, 20:15:35 UTC
Last enriched: 07/16/2026, 10:13:15 UTC
Last updated: 08/22/2026, 10:52:10 UTC
Views: 97
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