GHSA-9983-vrx2-fg9c — medium GitHub Advisory (CVE-2026-33222) in go/github.com/nats-io/nats-server/…

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.

Basic information

Type: reviewed
Severity: medium
Advisory on GitHub: Open advisory ↗
Repository advisory: Open repository advisory ↗
Source code: Browse source ↗
Published (advisory): 2026-03-24 21:49:34 UTC
Updated: 2026-03-27 22:10:19 UTC
GitHub reviewed: 2026-03-24 21:49:34 UTC
NVD published: 2026-03-25 21:16:47 UTC

Score	Percentile
0.03%	6.86%

CVSS Scores

Base score	Version	Severity	Vector
4.9	3.1	—	`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N` Click to expand Attack vector (AV:N) Could be attacked over the internet or any normal routed network—not just someone sitting at the machine. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:H) They need powerful rights—admin, root, or similar—before this pays off. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.

Identifiers

Type	Value
GHSA	GHSA-9983-vrx2-fg9c ↗
CVE	CVE-2026-33222 ↗

CWEs

CWE id	Name
CWE-285	Improper Authorization

Affected packages (3)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem	Package	Vulnerable range	First patched	Vulnerable functions
go	github.com/nats-io/nats-server/v2	< 2.11.15	2.11.15	—
go	github.com/nats-io/nats-server/v2	>= 2.12.0-RC.1, < 2.12.6	2.12.6	—
go	github.com/nats-io/nats-server	> 0	—	—

NATS JetStream has an authorization bypass through its Management API