CVE-2026-33217 (GCVE-0-2026-33217)

Vulnerability from cvelistv5 – Published: 2026-03-25 19:43 – Updated: 2026-06-30 12:07
VLAI
Title
NATS allows MQTT clients to bypass ACL checks
Summary
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, when using ACLs on message subjects, these ACLs were not applied in the `$MQTT.>` namespace, allowing MQTT clients to bypass ACL checks for MQTT subjects. Versions 2.11.15 and 2.12.6 contain a fix. No known workarounds are available.
Severity
7.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
8.1 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
SSVC
Exploitation: none Automatable: no Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
  • CWE-863 - Incorrect Authorization
  • CWE-425 - Direct Request ('Forced Browsing')
Assigner
References
Impacted products
Vendor Product Version
nats-io nats-server Affected: < 2.11.15
Affected: >= 2.12.0-RC.1, < 2.12.6
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Red Hat Multicluster Global Hub 1.4.5     cpe:/a:redhat:multicluster_globalhub:1.4::el9
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Red Hat Multicluster Global Hub 1.5.4     cpe:/a:redhat:multicluster_globalhub:1.5::el9
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Red Hat Multicluster Global Hub 1.6.2     cpe:/a:redhat:multicluster_globalhub:1.6::el9
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Red Hat Red Hat OpenShift Container Platform 4     cpe:/a:redhat:openshift:4
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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.