Cyber Resilience

CVE-2026-58210

DoS in Linuxfoundation Nats-Server ≤ 2.12.12

Published
08 July 2026
Modified
13 July 2026
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0050 40th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-58210 is a high-severity Uncontrolled Resource Consumption (CWE-400) vulnerability in Linuxfoundation Nats-Server. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Resource Hijacking (T1496); ranked at the 40th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SC-5 (Denial-of-service Protection) and SC-7 (Boundary Protection) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server…

more

memory while the parser waited for the advertised MQTT packet length. This issue is fixed in versions 2.14.3 and 2.12.12.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1496 Resource Hijacking Impact
Adversaries may leverage the resources of co-opted systems to complete resource-intensive tasks, which may impact system and/or hosted service availability.
Why these techniques?

The vulnerability allows an unauthenticated remote attacker to consume server memory via large incomplete MQTT CONNECT packets, which directly enables resource exhaustion (T1496 Resource Hijacking) against the messaging server.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-29785Same product: Linuxfoundation Nats-Server
CVE-2026-33216Same product: Linuxfoundation Nats-Server
CVE-2026-33223Same product: Linuxfoundation Nats-Server
CVE-2026-58209Same product: Linuxfoundation Nats-Server
CVE-2026-58214Same product: Linuxfoundation Nats-Server
CVE-2026-33219Same product: Linuxfoundation Nats-Server
CVE-2026-33222Same product: Linuxfoundation Nats-Server
CVE-2026-27571Same product: Linuxfoundation Nats-Server
CVE-2026-58254Same product: Linuxfoundation Nats-Server
CVE-2026-33215Same product: Linuxfoundation Nats-Server

Affected Assets

linuxfoundation
nats-server
≤ 2.12.12 · 2.14.0 — 2.14.3

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)
  • SC-7 Boundary Protection
  • SC-5 Denial-of-service Protection
  • SI-10 Information Input Validation
Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST 800-53 r5) AI

prevent

Boundary protection at the network perimeter can drop or rate-limit unauthenticated MQTT traffic before the server allocates memory for incomplete CONNECT packets.

prevent

Denial-of-service protection mechanisms can enforce connection-rate and resource-consumption limits that directly mitigate the memory-exhaustion attack described in CVE-2026-58210.

prevent

Input validation on the MQTT CONNECT packet length field can reject malformed or oversized packets before the parser allocates large buffers.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.IR-04 mostly match
prevents

Explicitly requires monitoring and maintaining resource capacity, directly addressing uncontrolled consumption to preserve availability.

DE.CM-09 partial match
prevents

Continuous monitoring of computing resources can detect resource exhaustion but does not itself enforce allocation limits.

PR.IR-03 partial match
prevents

Resilience mechanisms such as avoiding single points of failure indirectly reduce impact of resource exhaustion.

PR.PS-01 partial match
prevents

Hardened configuration baselines can include resource quotas and limits that constrain consumption.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Resource-utilization monitoring and alerting on bottlenecks or overloads limits the impact of denial-of-service or resource-exhaustion attacks.

prevents

By continuously monitoring utilization, stress-testing peak loads, and maintaining documented plans to scale or throttle resources, the control directly limits an attacker’s ability to drive a system into uncontrolled resource exhaustion.

detects

Pre-agreed severity-based prioritization and resource allocation during incident triage reduce the likelihood that an attacker-induced resource exhaustion will overwhelm the organization before corrective action is taken.

mitigates

Business-continuity plans that include resource-management controls reduce the likelihood that an attacker can trigger uncontrolled resource consumption by forcing the system into a degraded or fallback state.

mitigates

Defining RTOs and capacity requirements for ICT services during business-impact analysis forces organizations to provision sufficient resources and throttling mechanisms, reducing the likelihood that an attacker can induce denial-of-service through uncontrolled resource consumption.

detects

Early notification of anomalous resource consumption or system malfunctions enables throttling or isolation before availability is lost.

References