CVE-2026-33217

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 82% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 6.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
6.5
EG Score
6.5MEDIUMmedium confidence
EG Risk
29
EG Risk 29/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity65% × 45%
Exploitation0% × 40%
Automatability0% × 15%
EPSS PROB
0.4%
EPSS %ILE
28th
KEV
Not listed

Published

March 25, 2026

Last Modified

September 9, 2026

Advisory Details (8)

Auto-updated Jul 16, 2026
Patch available. Sources: github, redhat.
redhatMentions a patch (unverified)
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33217.json
redhat

2451446 – (CVE-2026-33217) CVE-2026-33217 nats-server: github.com/nats-io/nats-server: NATS-Server: Access control bypass via unapplied ACLs in MQTT namespace

https://bugzilla.redhat.com/show_bug.cgi?id=2451446
redhatMentions a patch (unverified)

cve-details

https://access.redhat.com/security/cve/CVE-2026-33217
redhatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:23345
redhatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:22347
redhatMentions a patch (unverified)
https://access.redhat.com/errata/RHSA-2026:21769
githubMentions a patch (unverified)

MQTT ACLs ineffective · Advisory · nats-io/nats-server · GitHub

https://github.com/nats-io/nats-server/security/advisories/GHSA-jxxm-27vp-c3m5
generic
https://advisories.nats.io/CVE/secnote-2026-07.txt

Vendor Advisories for CVE-2026-33217(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatmulticluster-globalhub/multicluster-globalhub-grafana-rhel9:17801671182026-06-04redhat
redhatmulticluster-globalhub/multicluster-globalhub-grafana-rhel9:17795794392026-06-01redhat
redhatmulticluster-globalhub/multicluster-globalhub-grafana-rhel9:17788677532026-05-28redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Go(2)
PackageVulnerable rangeFix by version rangeDependents
github.com/nats-io/nats-server—
  • every version on: no fix on record
—
github.com/nats-io/nats-server/v2—
  • every version up to 2.11.15: fixed in 2.11.15
  • 2.12.0-RC.1 up to 2.12.6: fixed in 2.12.6
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
nats-server2.10.1-1 ... 2.9.19-1 (15 versions)
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
nats-server2.10.27-1 ... 2.14.6-1 (6 versions)
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
nats-server2.10.27-1, 2.12.4-1
  • every version up to 2.12.6-1: fixed in 2.12.6-1
—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 7× in last 7d / 25× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 148 total refreshes for this CVE.

  1. 2026-10-09 20:07 UTCEPSS rescore
  2. 2026-10-08 17:12 UTCEPSS rescore
  3. 2026-10-07 23:47 UTCEPSS rescore
  4. 2026-10-06 15:17 UTCEPSS rescore
  5. 2026-10-05 17:42 UTCEPSS rescore
  6. 2026-10-04 23:22 UTCEPSS rescore
  7. 2026-10-03 14:25 UTCEPSS rescore
  8. 2026-10-01 19:49 UTCEPSS rescore
  9. 2026-09-30 15:03 UTCEPSS rescore
  10. 2026-09-29 07:15 UTCOSV refresh
  11. 2026-09-28 13:51 UTCEPSS rescore
  12. 2026-09-27 13:48 UTCEPSS rescore
  13. 2026-09-26 15:58 UTCEPSS rescore
  14. 2026-09-26 00:26 UTCEPSS rescore
  15. 2026-09-20 20:15 UTCEPSS rescore
  16. 2026-09-18 19:28 UTCEPSS rescore
  17. 2026-09-18 19:28 UTCEPSS rescore
  18. 2026-09-17 19:30 UTCEPSS rescore
  19. 2026-09-16 14:08 UTCEPSS rescore
  20. 2026-09-16 05:15 UTCEPSS rescore
  21. 2026-09-15 03:11 UTCEPSS rescore
  22. 2026-09-13 16:47 UTCEPSS rescore
  23. 2026-09-12 15:01 UTCEPSS rescore
  24. 2026-09-11 14:52 UTCEPSS rescore
  25. 2026-09-10 09:34 UTCEPSS rescore
Show 75 more
  1. 2026-09-09 13:42 UTCVendor advisory
  2. 2026-09-09 12:40 UTCEG score recompute
  3. 2026-09-09 12:40 UTCVendor advisory
  4. 2026-09-08 22:00 UTCEPSS rescore
  5. 2026-09-07 16:01 UTCEPSS rescore
  6. 2026-09-07 13:24 UTCEG score recompute
  7. 2026-09-07 13:24 UTCVendor advisory
  8. 2026-09-06 13:47 UTCEPSS rescore
  9. 2026-09-06 13:47 UTCEPSS rescore
  10. 2026-09-04 05:06 UTCEPSS rescore
  11. 2026-09-02 14:11 UTCEPSS rescore
  12. 2026-09-01 13:53 UTCEPSS rescore
  13. 2026-09-01 04:39 UTCEPSS rescore
  14. 2026-09-01 04:39 UTCEPSS rescore
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:41 UTCEPSS rescore
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-24 14:17 UTCEPSS rescore
  22. 2026-08-24 13:31 UTCVendor advisory
  23. 2026-08-24 12:27 UTCEG score recompute
  24. 2026-08-24 12:27 UTCVendor advisory
  25. 2026-08-23 00:19 UTCEPSS rescore
  26. 2026-08-21 23:49 UTCEPSS rescore
  27. 2026-08-20 22:55 UTCEPSS rescore
  28. 2026-08-20 22:55 UTCEPSS rescore
  29. 2026-08-19 17:03 UTCEPSS rescore
  30. 2026-08-18 13:48 UTCEPSS rescore
  31. 2026-08-17 13:47 UTCEPSS rescore
  32. 2026-08-17 12:21 UTCVendor advisory
  33. 2026-08-17 12:13 UTCEG score recompute
  34. 2026-08-17 12:13 UTCVendor advisory
  35. 2026-08-16 14:56 UTCEPSS rescore
  36. 2026-08-16 10:13 UTCEG score recompute
  37. 2026-08-16 10:13 UTCVendor advisory
  38. 2026-08-16 02:14 UTCEPSS rescore
  39. 2026-08-15 01:30 UTCEPSS rescore
  40. 2026-08-14 13:28 UTCVendor advisory
  41. 2026-08-14 12:30 UTCVendor advisory
  42. 2026-08-14 06:31 UTCEG score recompute
  43. 2026-08-14 06:31 UTCVendor advisory
  44. 2026-08-13 22:00 UTCEPSS rescore
  45. 2026-08-12 22:57 UTCEG score recompute
  46. 2026-08-12 22:57 UTCVendor advisory
  47. 2026-08-12 13:50 UTCEPSS rescore
  48. 2026-08-11 20:52 UTCEG score recompute
  49. 2026-08-11 20:52 UTCVendor advisory
  50. 2026-08-11 00:00 UTCEPSS rescore
  51. 2026-08-10 13:22 UTCVendor advisory
  52. 2026-08-10 12:27 UTCVendor advisory
  53. 2026-08-10 08:11 UTCEG score recompute
  54. 2026-08-10 08:11 UTCVendor advisory
  55. 2026-08-09 13:46 UTCEPSS rescore
  56. 2026-08-09 06:07 UTCEG score recompute
  57. 2026-08-09 06:07 UTCVendor advisory
  58. 2026-08-08 16:37 UTCEPSS rescore
  59. 2026-08-07 16:27 UTCEG score recompute
  60. 2026-08-07 16:27 UTCVendor advisory
  61. 2026-08-06 13:46 UTCEPSS rescore
  62. 2026-08-06 00:57 UTCEG score recompute
  63. 2026-08-06 00:57 UTCVendor advisory
  64. 2026-08-05 19:17 UTCEPSS rescore
  65. 2026-08-04 15:10 UTCEPSS rescore
  66. 2026-08-04 10:38 UTCEPSS rescore
  67. 2026-08-03 13:44 UTCVendor advisory
  68. 2026-08-03 12:49 UTCEG score recompute
  69. 2026-08-03 12:49 UTCVendor advisory
  70. 2026-08-03 10:36 UTCEPSS rescore
  71. 2026-08-02 15:27 UTCEG score recompute
  72. 2026-08-02 15:27 UTCVendor advisory
  73. 2026-08-02 02:27 UTCEPSS rescore
  74. 2026-08-01 04:16 UTCEPSS rescore
  75. 2026-07-30 16:28 UTCEPSS rescore

Related CVEs(same product + same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-33217?
CVE-2026-33217 is a medium vulnerability published on March 25, 2026. 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…
When was CVE-2026-33217 disclosed?
CVE-2026-33217 was first published on March 25, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-33217 actively exploited?
CVE-2026-33217 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (28th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-33217?
CVE-2026-33217 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-33217?
A fix for CVE-2026-33217 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-33217 are linked in the Vendor Advisories panel on this page.

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