CVE-2020-28466 Denial of Service (DoS)
Untrusted accounts can crash the NATS server by exploiting service export/import cycles, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-28466?
CVE-2020-28466 is a high-severity denial of service vulnerability in github.com/nats-io/nats-server/server, published on 7 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
This affects all versions of package github.com/nats-io/nats-server/server. Untrusted accounts are able to crash the server using configs that represent a service export/import cycles. Disclaimer from the maintainers: Running a NATS service which is exposed to untrusted users presents a heightened risk. Any remote execution flaw or equivalent seriousness, or denial-of-service by unauthenticated users, will lead to prompt releases by the NATS maintainers. Fixes for denial of service issues with no threat of remote execution, when limited to account holders, are likely to just be committed to the main development branch with no special attention. Those who are running such services are encouraged to build regularly from git.
Which versions are affected by CVE-2020-28466?
7 open source packages ship an affected version, including github.com/nats-io/nats-server, nats and github.com/nats-io/nats-server/v2. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
github.com/nats-io/nats-server Go | All versions | None |
github.com/nats-io/nats-server Go | All versions | 2.2.0 |
github.com/nats-io/nats-server Go | All versions | 2.2.0 |
nats Bitnami | From 2.0.0 | 2.2.0 |
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
1 more packages
github.com/nats-io/nats-server/v2 Go | All versions | 2.2.0 |
Products include Linuxfoundation Nats-Server.
How do I fix CVE-2020-28466?
Upgrade github.com/nats-io/nats-server to 2.2.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-28466 being exploited?
There is no known exploitation of CVE-2020-28466 in the wild and no public exploit code.
Other vulnerabilities in github.com/nats-io/nats-server/server
- CVE-2022-28357 NATS nats-server allows directory traversal via unintended path to a management action
- CVE-2026-58253 NATS Server: Route API Auth Bypass
- CVE-2022-24450 Incorrect Authorization in NATS nats-server
- CVE-2026-33216 NATS has MQTT plaintext password disclosure
- CVE-2026-58207 NATS Server: Remote crash via integer overflow in Connz pagination
Sources
Also known as BIT-nats-2020-28466, GHSA-m4jx-6526-vvhm, GO-2022-0855, SNYK-GOLANG-GITHUBCOMNATSIONATSSERVERSERVER-1042967.