Security readout for executives and security teams
Plain-English summary
NATS Server MQTT deployments can leak plaintext MQTT passwords through monitoring endpoints when usercodes/passwords are used. The issue is confidentiality-only but severe because an unauthenticated network user could read credentials if monitoring is reachable from an untrusted network.
Executive priority
Prioritize remediation for any Internet-exposed or shared-network monitoring endpoint. The business issue is credential leakage, not service outage, but leaked passwords can create broader access risk.
Technical view
Affected nats-server versions mishandle MQTT passwords by classifying them as a non-authenticating identity statement, causing plaintext exposure via monitoring endpoints. The provided record lists affected versions as <2.11.15 and >=2.12.0-RC.1 to <2.12.6. CVSS is 8.6 with network, low-complexity, unauthenticated access and high confidentiality impact.
Likely exposure
Exposure is most likely where NATS Server uses MQTT authentication with usercodes/passwords and monitoring endpoints are reachable by the Internet, partners, tenants, or other untrusted network users.
Exploitation context
No KEV listing is provided, and the source bundle does not state active exploitation. The main risk is credential disclosure from exposed monitoring endpoints, which could enable follow-on unauthorized access depending on where reused or trusted.
Researcher notes
The source bundle contains a fixed-version inconsistency: affected ranges imply 2.11.15 fixes the 2.11 branch, while the description also says 2.11.14 contains a fix. Treat vendor advisory confirmation as necessary before closing 2.11.x findings.
Mitigation direction
- Upgrade affected nats-server deployments to vendor-fixed releases.
- For 2.12 deployments, update to 2.12.6 or later.
- Verify the exact fixed 2.11.x release with vendor guidance due source inconsistency.
- Restrict monitoring endpoints to trusted administrators and private networks.
- Remove any public or unauthenticated access to monitoring endpoints.
- Rotate MQTT passwords that may have been exposed.
Validation and detection
- Inventory nats-server versions and identify MQTT-enabled deployments.
- Confirm whether MQTT usercodes/passwords are configured.
- Check monitoring endpoint exposure from untrusted networks.
- Review access logs for unexpected monitoring endpoint access.
- Verify monitoring endpoints require appropriate network or authentication controls.
- Confirm remediated instances run non-affected vendor-fixed versions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-213: Exact CWE lookup
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Open ATT&CK lookupCWE-256: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-33216 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.6 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N3.94GitHub_MCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N3.94redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Base CVSS 3.1 score
8.6HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-03-25T20:02:03.000Z: Reported to Red Hat.
- 2026-03-25T19:41:55.670Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/nats-io/nats-server/security/advisories/GHSA-v722-jcv5-w7mcCVE reference, GitHub_M · x_refsource_CONFIRM
- https://github.com/nats-io/nats-server/commit/b5b63cfc35a57075e09c1f57503d31721bed8099CVE reference, GitHub_M · x_refsource_MISC
- https://advisories.nats.io/CVE/secnote-2026-05.txtCVE reference, GitHub_M · x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-33216CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2451448CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33216.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
- https://access.redhat.com/errata/RHSA-2026:22347CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:23345CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/errata/RHSA-2026:21769CVE reference, redhat-SADP · vendor-advisory, x_refsource_REDHAT
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Exposure of Sensitive Information Due to Incompatible Policies
Exposure of Sensitive Information Due to Incompatible Policies represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Plaintext Storage of a Password
Plaintext Storage of a Password represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.