Auth bypass in Linuxfoundation Nats-Server
CVE-2026-58252
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.
EPSS: 0.003 (27.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Linuxfoundation Nats-server
- Nats-io Nats-server — versions < 2.11.16, >= 2.12.0-preview.1, < 2.12.7
Weakness classification (CWE)
References
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-58252?
- CVE-2026-58252 is a medium-severity vulnerability in Linuxfoundation Nats-Server, classified under Improper Authorization. CVSS score: 6.5/10. Published 2026-07-08.
- How severe is CVE-2026-58252?
- Medium severity. CVSS v3 base score is 6.5 out of 10.