# CVE-2026-58251: NATS Server: Queue Subscribe Authz Bypass

> Authenticated users can bypass subscription deny permissions via queue subscriptions, allowing unauthorized message access in NATS Server.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 8 Jul 2026
- **Updated:** 9 Jul 2026
- **Also known as:** AZL-92244, BIT-nats-2026-58251, DEBIAN-CVE-2026-58251, GHSA-jx8g-9g95-6322, JLSEC-2026-1151, MINI-6x3w-g856-jcc2, MINI-jf65-rw3j-gxxc, UBUNTU-CVE-2026-58251

## What is CVE-2026-58251?

CVE-2026-58251 is a medium-severity authentication bypass vulnerability in nats-io nats-server, published on 8 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

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, an authenticated user with subscription deny permissions could bypass a plain subject deny rule by using a queue subscription, because queue-specific deny evaluation could override the plain subject deny result when the queue name itself was not denied. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-58251?

1 open source package ship an affected version, including nats. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `nats` | Bitnami | All versions | 2.11.16, 2.12.7 |

Products: Linuxfoundation Nats-Server.

## How do I fix CVE-2026-58251?

Upgrade nats to a fixed version for your release line: 2.11.16 or 2.12.7.

## Is CVE-2026-58251 being exploited?

There is no known exploitation of CVE-2026-58251 in the wild and no public exploit code.

## Other vulnerabilities in nats-io nats-server

- [CVE-2022-28357](https://insights.sbomify.com/CVE-2022-28357/): NATS nats-server allows directory traversal via unintended path to a management action (critical 9.8)
- [CVE-2026-58253](https://insights.sbomify.com/CVE-2026-58253/): NATS Server: Route API Auth Bypass (high 8.8)
- [CVE-2022-24450](https://insights.sbomify.com/CVE-2022-24450/): Incorrect Authorization in NATS nats-server (high 8.8)
- [CVE-2026-33216](https://insights.sbomify.com/CVE-2026-33216/): NATS has MQTT plaintext password disclosure (high 8.6)
- [CVE-2026-58207](https://insights.sbomify.com/CVE-2026-58207/): NATS Server: Remote crash via integer overflow in Connz pagination (high 7.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58251 and fix it if it is affected.

What it is: CVE-2026-58251 is a medium-severity authentication bypass vulnerability in nats-io nats-server, published on 8 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-58251 in the wild and no public exploit code.

Affected packages and fixed versions:
- nats (Bitnami): affected all versions; fixed in 2.11.16, 2.12.7

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-58251/ (Markdown: https://insights.sbomify.com/CVE-2026-58251/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58251
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58251
- OSV: https://osv.dev/vulnerability/CVE-2026-58251

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58251/
Summaries are generated and may contain mistakes; the official description above is the record.