CVE-2026-58252: CWE-285: Improper Authorization in nats-io nats-server
NATS Server versions prior to 2.14.0, 2.12.7, and 2.11.16 contain an improper authorization vulnerability where authenticated users could receive messages on subjects they are denied access to due to overlapping wildcard subscription rules. This issue affects message delivery and queue subscriptions. The vulnerability 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. Authenticated users 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 influence message delivery to legitimate queue consumers. This flaw allows unauthorized message reception despite access controls. The issue is resolved in nats-server versions 2.14.0, 2.12.7, and 2.11.16.
Potential Impact
The vulnerability allows authenticated users to bypass subject-level deny rules under certain wildcard subscription configurations, potentially exposing sensitive messages to unauthorized recipients. The confidentiality of messages is impacted (high confidentiality impact), but integrity and availability are not affected. There are no known exploits in the wild.
Mitigation Recommendations
Upgrade nats-server to version 2.14.0, 2.12.7, or 2.11.16 or later to apply the official fix. Patch status is confirmed by the vendor advisory indicating these versions contain the fix. No additional mitigations are specified.
CVE-2026-58252: CWE-285: Improper Authorization in nats-io nats-server
Description
NATS Server versions prior to 2.14.0, 2.12.7, and 2.11.16 contain an improper authorization vulnerability where authenticated users could receive messages on subjects they are denied access to due to overlapping wildcard subscription rules. This issue affects message delivery and queue subscriptions. The vulnerability 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. Authenticated users 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 influence message delivery to legitimate queue consumers. This flaw allows unauthorized message reception despite access controls. The issue is resolved in nats-server versions 2.14.0, 2.12.7, and 2.11.16.
Potential Impact
The vulnerability allows authenticated users to bypass subject-level deny rules under certain wildcard subscription configurations, potentially exposing sensitive messages to unauthorized recipients. The confidentiality of messages is impacted (high confidentiality impact), but integrity and availability are not affected. There are no known exploits in the wild.
Mitigation Recommendations
Upgrade nats-server to version 2.14.0, 2.12.7, or 2.11.16 or later to apply the official fix. Patch status is confirmed by the vendor advisory indicating these versions contain the fix. No additional mitigations are specified.
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: 07/08/2026, 20:29:08 UTC
Last updated: 07/08/2026, 20:29:08 UTC
Views: 2
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