Vulnerability · CVE-2026-33246
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system.
Published Mar 25, 2026 · catalog updated Jun 17, 2026 · NATS-Server is a High-Performance
Check if you run it
No confirmed exploitation is on record for CVE-2026-33246. EPSS is 0.24%. Act only if a listed version of NATS-Server is a High-Performance is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (NATS-Server is a High-Performance).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- Severity
- Medium5.4
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.24%
- Remediation
- Advisory link
- Affected products
- cpe linuxfoundation/nats-server
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a message header, providing information about a request. This is supposed to provide enough information to allow for account/user identification, such that NATS clients could make their own decisions on how to trust a message, provided that they trust the nats-server as a broker. A leafnode connecting to a nats-server is not fully trusted unless the system account is bridged too. Thus identity claims should not have propagated unchecked. Prior to versions 2.11.15 and 2.12.6, NATS clients relying upon the Nats-Request-Info: header could be spoofed. This does not directly affect the nats-server itself, but the CVSS Confidentiality and Integrity scores are based upon what a hypothetical client might choose to do with this NATS header. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe linuxfoundation/nats-serverversion unspecified
How to fix CVE-2026-33246
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-33246. EPSS is 0.24%. Act only if a listed version of NATS-Server is a High-Performance is installed.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-287: Improper Authentication; CWE-290: Authentication Bypass by Spoofing. EPSS 0.24%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Mar 25, 2026 · NIST NVD
Detected
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a message header, providing information about a request. This is supposed to provide enough information to allow for account/user identification, such that NATS clients could make their own decisions on how to trust a message, provided that they trust the nats-server as a broker.
Jun 17, 2026 · NIST NVD
Updated
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a message header, providing information about a request. This is supposed to provide enough information to allow for account/user identification, such that NATS clients could make their own decisions on how to trust a message, provided that they trust the nats-server as a broker.
Sources
- CVE.orgVulnerability recordCVE-2026-33246
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-33246
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-2026-33246
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a message header, providing information about a request. This is supposed to provide enough information to allow for account/user identifica
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.