GHSA-9983-vrx2-fg9c BIT-nats-2026-33222 CVE-2026-33222 GO-2026-4832

NATS JetStream has an authorization bypass through its Management API

Medium Go

Severity: 4.9 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 0.32%; Chance of exploitation in the next 30 days. Higher than 24.81% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-285 Improper Authorization
Fix: 2.11.15; Upgrade github.com/nats-io/nats-server/v2 to this version or later

Description

Background

NATS.io is a high performance open source pub-sub distributed communication technology, built for the cloud, on-premise, IoT, and edge computing.

The persistent storage feature, JetStream, has a management API which has many features, amongst which are backup and restore.

Problem Description

Users with JetStream admin API access to restore one stream could restore to other stream names, impacting data which should have been protected against them.

Affected Versions

Any version before v2.12.6 or v2.11.15

Workarounds

If developers have configured users to have limited JetStream restore permissions, temporarily remove those permissions.

Affected versions

Go

Package	Vulnerable	Fixed in
github.com/nats-io/nats-server	`all versions`	No fix yet
github.com/nats-io/nats-server/v2	`< 2.11.15`	`2.11.15`
github.com/nats-io/nats-server/v2	`>= 2.12.0-RC.1, < 2.12.6`	`2.12.6`
github.com/nats-io/nats-server/v2	`< 2.11.15` `>= 2.12.0-RC.1, < 2.12.6`	`2.11.15` `2.12.6`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

github.com/nats-io/nats-server/v2 Go → `2.11.15`

go

go get github.com/nats-io/nats-server/v2@v2.11.15 && go mod tidy

Severity breakdown

CVSS 3.1 4.9

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

Attack vector: Network
Attack complexity: Low
Privileges required: High
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Weakness

CWE-285: Improper Authorization

The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.

How to prevent it

Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
Architecture and Design: Ensure that you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2026-33222

Packages

github.com/nats-io/nats-server

Timeline

Mar 24, 2026 Published
Sep 10, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-pq2q-rcw4-3hr6 NATS: Pre-auth remote server crash via WebSocket frame length overflow in wsRead	High	Also affects github.com/nats-io/nats-server
GHSA-3f24-pcvm-5jqc NATS has mTLS verify_and_map authentication bypass via incorrect Subject DN matching	Medium	Also affects github.com/nats-io/nats-server
GHSA-55h8-8g96-x4hj NATS: Leafnode connections allow spoofing of Nats-Request-Info identity headers	Medium	Also affects github.com/nats-io/nats-server
GHSA-pwx7-fx9r-hr4h NATS Server: Incomplete Stripping of Nats-Request-Info Header Allows Identity Spoofing	Medium	Also affects github.com/nats-io/nats-server
GHSA-8r68-gvr4-jh7j NATS is vulnerable to pre-auth DoS through WebSockets client service	Medium	Also affects github.com/nats-io/nats-server
GHSA-vprv-35vv-q339 NATS has pre-auth server panic via leafnode handling	High	Also affects github.com/nats-io/nats-server
GHSA-jxxm-27vp-c3m5 NATS allows MQTT clients to bypass ACL checks	Medium	Also affects github.com/nats-io/nats-server
GHSA-v722-jcv5-w7mc NATS has MQTT plaintext password disclosure	High	Also affects github.com/nats-io/nats-server

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