Nats server: Prior to 2.14.3 and 2.12.12, an authenticated MQTT client could subscribe to the internal
Affects nats-serverSource GCVE Database
Not known to be exploited · CVSS 4.3 Medium · fixed in 2.14.3 : update nats-server when convenient.
Data as of 26 Oct 2026, 11:07 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Affects
- NATS Server prior to 2.14.3
- Patch
- Available – fixed in 2.14.3
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10nats-serverpkg:deb/ubuntu/nats-server?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu Pro 26.04 LTSnats-serverpkg:deb/ubuntu/nats-server?arch=source&distro=esm-apps/resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10nats-serverpkg:deb/ubuntu/nats-server?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSnats-serverpkg:deb/ubuntu/nats-server?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade NATS Server to version 2.14.3 or 2.12.12 or later, where this vulnerability is fixed. No other mitigation is indicated by the vendor advisory.
Description
CVE-2026-58214 is a vulnerability in NATS Server versions prior to 2.14.3 and 2.12.12 where an authenticated MQTT client can bypass subscription access controls by subscribing to the internal $MQTT.deliver.pubrel subject prefix. This exposure allows access to MQTT QoS2 protocol metadata for sessions within the account. The issue is fixed in versions 2.14.3 and 2.12.12.
References
- ubuntu.com/security/CVE-2026-58214 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-58214 (opens in a new tab)
- github.com/nats-io/nats-server/security/advisories/GHSA-4g68-3pwx-5vfj (opens in a new tab)
- github.com/nats-io/nats-server/commit/297b166be60fe13144084eed4b25201ead03204a (opens in a new tab)
- github.com/nats-io/nats-server/commit/34b09657bb596d5f850eaa5cfc97ea6b2f989a97 (opens in a new tab)
- github.com/nats-io/nats-server/releases/tag/v2.12.12 (opens in a new tab)
- github.com/nats-io/nats-server/releases/tag/v2.14.3 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-58214 (opens in a new tab)