NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an authenticated MQTT client could subscribe to the internal $MQTT.deliver.pubrel subject family, bypassing configured subscribe permissions and exposing MQTT QoS2 protocol metadata for sessions in the account. This issue is fixed in versions 2.14.3 and 2.12.12.
CVE-2026-58214
This medium-severity CVE scores 4.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 71% 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).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 4.3
- EG Score
- 4.3(medium)
- EPSS
- 27.0%
- KEV
- Not listed
Published
July 8, 2026
Last Modified
July 13, 2026
Advisory Details (5)
Auto-updated Jul 8, 2026MQTT subscribe ACL bypass via $MQTT.deliver.pubrel prefix (incomplete fix for CVE-2026-33217) · Advisory · nats-io/nats-server · GitHub
Affected: v2.14.3 and v2.12.8.
https://github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfjRelease v2.14.3
Patch available: nats-io/nats-server v2.14.3
https://github.com/nats-io/nats-server/releases/tag/v2.14.3Release v2.12.12
Patch available: nats-io/nats-server v2.12.12
https://github.com/nats-io/nats-server/releases/tag/v2.12.12commit 34b09657bb59 (nats-io/nats-server)
Fix landed in nats-io/nats-server commit 34b09657bb59 — awaiting tagged release
https://github.com/nats-io/nats-server/commit/34b09657bb596d5f850eaa5cfc97ea6b2f989a97commit 297b166be60f (nats-io/nats-server)
Fix landed in nats-io/nats-server commit 297b166be60f — awaiting tagged release
https://github.com/nats-io/nats-server/commit/297b166be60fe13144084eed4b25201ead03204aWeakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 18× in last 7d / 18× 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.
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-14 19:39 UTCEG score recompute
- 2026-07-13 22:31 UTCEPSS rescore
- 2026-07-13 19:46 UTCEG score recompute
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 19:52 UTCEG score recompute
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 19:58 UTCEG score recompute
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-10 20:04 UTCEG score recompute
- 2026-07-09 20:09 UTCEG score recompute
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 20:16 UTCEG score recompute
- 2026-07-08 20:14 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-863
Frequently asked(5)
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