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© 2026 FAUCET Technologies LLC. All rights reserved.

CVE-2026-58253

39
FAUCET Score

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.

First published: Jul 8, 2026Last modified: Jul 8, 2026

Impacted Technologies

VendorProductVersion(s)CPE
< 2.11.16CPE matchmatch criteria
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*
>= 2.12.0, < 2.12.7CPE matchmatch criteria
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 3.1

8.8HIGH

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L

Attack Vector
ADJACENT_NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
LOW
Integrity Impact
HIGH
Availability Impact
LOW
Exploitability Score
2.8
Impact Score
5.3
CvssVersion
3.1

Exploit Intelligence

EPSS Score
0.23%
Probability of exploitation in next 30 days
EPSS Percentile
13.5%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
This CVE's current EPSS score of 0.0023 is in the 8th percentile among its peer group of 1,859 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.2 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (2)

microsoftpatch availablevia msrc
Product: azl3 telegraf 1.31.0-23 on Azure Linux 3.0Fixed in: 1.31.0-24
microsoftpatch availablevia msrc
Product: 21481-17084Fixed in: 1.31.0-24

Vendor Advisories (1)

microsoft2026-Jul/CVE-2026-58253Important

NATS Server: Route API Auth Bypass

Jul 2, 2026

References

github.com / nats-io/nats-server/commit/7b81dd455ea95960090a84858c7662827948d1b6
Patch
github.com / nats-io/nats-server/commit/8b8e1ad4ceed32321e00d4fc6e76be05bc13bca6
Patch
github.com / nats-io/nats-server/commit/b86147e81710a52b72a7f7275f91d69f723f5cb3
Patch
github.com / nats-io/nats-server/releases/tag/v2.11.16
Release Notes
github.com / nats-io/nats-server/releases/tag/v2.12.7
Release Notes
github.com / nats-io/nats-server/releases/tag/v2.14.0
Release Notes
github.com / nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45
Vendor Advisory