NATS: Leafnode connections allow spoofing of Nats-Request-Info identity headers (nats-io nats-server)

CVE-2026-33246
MEDIUM 6.4

At a glance

Source
NVD
EPSS
EPSS 0.15 % · percentile 4 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Analyzed

Description

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server offers a `Nats-Request-Info:` 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.

Weaknesses (CWE)

  • CWE-287 — Improper Authentication
  • CWE-290 — Authentication Bypass by Spoofing

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 6.4CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:NGitHub_M
CVSS 3.1MEDIUM 6.4CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:NNVD · security-advisories@github.com (Secondary)
CVSS 3.1MEDIUM 5.4CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:NNVD · nvd@nist.gov (Primary)

Advisories

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
nats-io · nats-serveraffected < 2.11.15 ; affected >= 2.12.0-RC.1, < 2.12.6

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD