NATS Server: Queue Subscribe Authz Bypass (CVE-2026-58251)
NATS Server versions prior to 2.14.0, 2.12.7, and 2.11.16 contain an authorization bypass vulnerability. An authenticated user with subscription deny permissions could bypass a plain subject deny rule by using a queue subscription if the queue name itself was not denied. This issue has been fixed in versions 2.14.0, 2.12.7, and 2.11.16.
AI Analysis
Technical Summary
NATS Server, a high-performance messaging server for NATS.io, had a vulnerability (CVE-2026-58251) where an authenticated user with subscription deny permissions could bypass a plain subject deny rule by leveraging queue subscriptions. The queue-specific deny evaluation could override the plain subject deny result when the queue name was not explicitly denied, allowing unauthorized subscription access. This flaw affects versions prior to 2.14.0, 2.12.7, and 2.11.16 and has been addressed in those fixed versions.
Potential Impact
The vulnerability allows an authenticated user to bypass subscription deny permissions under specific conditions, potentially enabling unauthorized message subscription access. This could lead to unauthorized data access within the messaging system. There are no known exploits in the wild at this time.
Mitigation Recommendations
A patch is available and the issue is fixed in NATS Server versions 2.14.0, 2.12.7, and 2.11.16. Users should upgrade to these or later versions to remediate the vulnerability.
NATS Server: Queue Subscribe Authz Bypass (CVE-2026-58251)
Description
NATS Server versions prior to 2.14.0, 2.12.7, and 2.11.16 contain an authorization bypass vulnerability. An authenticated user with subscription deny permissions could bypass a plain subject deny rule by using a queue subscription if the queue name itself was not denied. This issue has been fixed in versions 2.14.0, 2.12.7, and 2.11.16.
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 high-performance messaging server for NATS.io, had a vulnerability (CVE-2026-58251) where an authenticated user with subscription deny permissions could bypass a plain subject deny rule by leveraging queue subscriptions. The queue-specific deny evaluation could override the plain subject deny result when the queue name was not explicitly denied, allowing unauthorized subscription access. This flaw affects versions prior to 2.14.0, 2.12.7, and 2.11.16 and has been addressed in those fixed versions.
Potential Impact
The vulnerability allows an authenticated user to bypass subscription deny permissions under specific conditions, potentially enabling unauthorized message subscription access. This could lead to unauthorized data access within the messaging system. There are no known exploits in the wild at this time.
Mitigation Recommendations
A patch is available and the issue is fixed in NATS Server versions 2.14.0, 2.12.7, and 2.11.16. Users should upgrade to these or later versions to remediate the vulnerability.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-58251
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:Pro:26.04:LTS"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a58b45d68715ace43d6be30
Added to database: 07/16/2026, 10:37:17 UTC
Last enriched: 09/08/2026, 15:19:32 UTC
Last updated: 09/10/2026, 20:22:47 UTC
Views: 26
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