nats-server: Plaintext Storage of a Password
CVE-2026-33216 is a high-severity plaintext storage of a password vulnerability in nats-server from Nats-io, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected nats-server versions: < 2.11.15; >= 2.12.0-RC.1, < 2.12.6. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.38% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of nats-server you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on advisories.nats.io for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Nats-io | nats-server | < 2.11.15; >= 2.12.0-RC.1, < 2.12.6 | Not stated |
| Red Hat | Multicluster Global Hub 1.4.5 | Not specified in the record | Not stated |
| Red Hat | Multicluster Global Hub 1.6.5 | Not specified in the record | Not stated |
| Red Hat | Red Hat multicluster global hub 1.5.3 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.6 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 8.6 | High | CNA |
Official description
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, for MQTT deployments using usercodes/passwords: MQTT passwords are incorrectly classified as a non-authenticating identity statement (JWT) and exposed via monitoring endpoints. Versions 2.11.14 and 2.12.6 contain a fix. As a workaround, ensure monitoring end-points are adequately secured. Best practice remains to not expose the monitoring endpoint to the Internet or other untrusted network users.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Plaintext Storage of a Password
The product stores a password in plaintext within resources such as memory or files.
How developers prevent this class of flaw
- Avoid storing passwords in easily accessible locations.
- Consider storing cryptographic hashes of passwords as an alternative to storing in plaintext.
- A programmer might attempt to remedy the password management problem by obscuring the password with an encoding function, such as base 64 encoding, but this effort does not adequately protect the password because the encoding can be detected and decoded easily.
More Plaintext Storage of a Password vulnerabilities (CWE-256)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
Other references
Other vulnerabilities in nats-server
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 7.1 High severity
- 7.5 High severity
- 7.5 High severity
Recent Plaintext Storage of a Password vulnerabilities
- 9.8 Critical severity
- 7.2 High severity
- 7.1 High severity
- 7.5 High severity
- 8.7 High severity
- 9.8 Critical severity
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