SecOps SignalSecurity Intelligence Workspace
Loading collection status
Vulnerabilities/CVE-2026-58253Public Intelligence Dossier
Source: linuxfoundation · Limited verification•Last verified: •Collection Degraded
CVE-2026-58253Unknown / EvaluatingHIGH (raw)CVSS 8.8CWE-287

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system

Published: 09 Jul 2026•Last updated: 25 Oct 2026, 10:40 PM IST•Source identifier: security-advisories@github.com
Dossier completeness: source-provided sections 2 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Unknown
KEV status was not determined.
CVSS score
8.8HIGH (raw)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
Metric sourcesecurity-advisories@github.com
EPSS probability
0.4%0.004
Percentile31st
Weakness type
CWE-287
No further CWE recorded
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

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.

SOC priority

High

Actively exploited (source statement)

Unknown

Publicly disclosed

Unknown

Risk basis: Microsoft or Microsoft-managed product relevance; HIGH severity; Source severity; no confirmed exploitation signal

Affected Products & Remediation

1 source-backed product
Affected products and versions (source)
  • linuxfoundation nats-server · < 2.11.16; >= 2.12.0 < 2.12.7 · NVD CPE · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

Not provided by source

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Unknown
Exploited (source statement)
Unknown
Publicly disclosed (source)
Unknown

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

Matched authentication-weakness (CWE-287)

Exposure

  1. Identify affected authentication surfaces and compare versions with the advisory.Telemetry: Application inventory · A CWE match is not proof of local exposure. · Rule authentication-weakness

Exploitation evidence

  1. Review unexpected successful sign-ins and changes to privileged accounts on affected systems.Telemetry: SigninLogs · Access anomalies are relevant to authentication weaknesses. · Rule authentication-weakness

Response

  1. Verify the vendor fix and review privileged access after remediation.Telemetry: Identity audit logs · Post-change review checks the response. · Rule authentication-weakness

CISA KEV Record

CISA KEV status was not determined for this record.

Change History & Source Data

— No recorded material change

CNA / source
security-advisories@github.com
Record status · verification
UPDATED · NVD API
CPE
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*

Evidence & Provenance

3 public sources
github.comSource recordnvd.nist.govSource recordgithub.comSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2026-58253
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2026-58253
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-58253"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
Open KQL Library

Looking up related community queries…

Loading related intelligence

Correlated briefings

SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.