TI-2026-41922 Aliases CVE-2026-58213

NATS Server: MQTT SUBSCRIBE Protocol Injection via Leaf Node/Route Forwarding allows arbitrary NATS command injection

LOW 32CWE-74Published 2026-07-08 · Updated 2026-07-09

Key facts

Attack vector: Network
Privileges required: Low
User interaction: None
Attack complexity: Low
Impact type: —
Confidentiality · integrity · availability: High · Low · None
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.1 and 2.12.9, an MQTT client could include protocol control characters in subscription filters that were later forwarded as NATS protocol data to route or leafnode connections, corrupting the forwarded protocol stream and allowing injection of unintended NATS protocol operations. This issue is fixed in versions 2.14.1 and 2.12.9.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00441 38th percentileScored 2026-11-07

Fix Fixed nats-server (nats-io): 2.12.9, 2.14.1Red Hat: 2 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
backstage	nats-server	before 2.12.9; 2.14.0-RC.1 to before 2.14.1	2.12.9, 2.14.1	Patch available	CNA

nats-server Vendorbackstage Affected before 2.12.9; 2.14.0-RC.1 to before 2.14.1 Fixed in 2.12.9, 2.14.1 Patch available CNA

CPE configurations NVD · 1

CPE	Versions	Role	Vendor
cpe:2.3:a:linuxfoundation:nats-server::::::::	before 2.12.9; 2.14.0 to before 2.14.1	Vulnerable	backstage

cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:* Versions before 2.12.9; 2.14.0 to before 2.14.1 Vulnerable ·backstage

Remediation

Fix · CNA nats-server (nats-io) Fixed in 2.12.9, 2.14.1

Red Hat 2 advisories

RHSA-2026:36017 Released 2026-07-06 · Red Hat rating Important
Red Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images nats-server2-12-main@aarch64, nats-server2-12-main@src, nats-server2-12-main@x86_64
RHSA-2026:36016 Released 2026-07-06 · Red Hat rating Important
Red Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images nats-server2-14-main@aarch64, nats-server2-14-main@src, nats-server2-14-main@x86_64

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Hardened Images	Fixed	RHSA-2026:36016, RHSA-2026:36017

Timeline

2026-10-02 Threatist record created from CVE-2026-58213

References

Patch 5

Advisory 1

https://github.com/nats-io/nats-server/security/advisories/GHSA-qrcv-3558-gj4f

Other 2

TI-2026-22233 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead CVSS 3.1HIGH 7.5
TI-2022-11116 NATS nats-server 2.2.0 through 2.7.4 allows directory traversal because of an unintended… CVSS 3.1CRITICAL 9.8
TI-2020-16319 The JWT library in NATS nats-server before 2.1.9 has Incorrect Access Control because of… CVSS 3.1CRITICAL 9.8
TI-2026-25637 NATS has MQTT plaintext password disclosure CVSS 3.1HIGH 8.6
TI-2022-08320 NATS nats-server before 2.7.2 has Incorrect Access Control. CVSS 3.1HIGH 8.8
TI-2026-41950 NATS Server: Pre-auth server crash via double INFO in leafnode handshake CVSS 3.1HIGH 7.5

See all 35 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences