CVE-2026-58252: NATS Server: Subscribe Authz Bypass via Wildcard-Overlap
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.
Other sources
NATS Server: Subscribe Authz Bypass via Wildcard-Overlap
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.31.0-24 - Upgrade
Upgrade
NATS Serverto a version that resolves this vulnerability.Fixed in 2.14.0 - Upgrade
Upgrade
NATS Serverto a version that resolves this vulnerability.Fixed in 2.12.7 - Upgrade
Upgrade
NATS Serverto a version that resolves this vulnerability.Fixed in 2.11.16
Event History
Frequently Asked Questions
What is the severity of CVE-2026-58252?
CVE-2026-58252 has a medium severity rating of 6.5.
What systems are affected by CVE-2026-58252?
CVE-2026-58252 affects NATS Server versions prior to 2.14.0, 2.12.7, and 2.11.16.
How do I fix CVE-2026-58252?
To fix CVE-2026-58252, upgrade to NATS Server version 2.14.0 or later, or to 2.12.7 or later, or to 2.11.16 or later.
What is the nature of the vulnerability in CVE-2026-58252?
CVE-2026-58252 is an authorization bypass issue allowing an authenticated user to receive messages on denied subjects due to wildcard subscription overlap.
Can I mitigate CVE-2026-58252 without an upgrade?
Mitigating CVE-2026-58252 without an upgrade is not recommended, as the root cause lies in the server's handling of wildcard subscriptions.