CVE-2026-58253
NATS Server: Route API Auth Bypass
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, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.
INFO
Published Date :
July 8, 2026, 8:16 p.m.
Last Modified :
July 8, 2026, 8:16 p.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-58253
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update NATS Server to version 2.14.0 or later.
- Ensure no_auth_user is not configured when it's not needed.
- Configure inter-server CONNECT authentication properly.
- Monitor inter-server communication for unauthorized access.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-58253.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-58253 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-58253
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-58253 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-58253 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'nats-io', 'product': 'nats-server', 'versions': [{'status': 'affected', 'version': '< 2.11.16'}, {'status': 'affected', 'version': '>= 2.12.0-preview.1, < 2.12.6'}]}] Added 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, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16. Added CVSS V3.1 AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L Added CWE CWE-287 Added Reference https://github.com/nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6 Added Reference https://github.com/nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6 Added Reference https://github.com/nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3 Added Reference https://github.com/nats-io/nats-server/releases/tag/v2.11.16 Added Reference https://github.com/nats-io/nats-server/releases/tag/v2.12.7 Added Reference https://github.com/nats-io/nats-server/releases/tag/v2.14.0 Added Reference https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45