Nats server: Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large
Affects nats-serverSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 2.14.3 : patch nats-server soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.14.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation 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 mitigations are indicated or required.
Description
NATS Server versions prior to 2.14.3 and 2.12.12 contain a vulnerability where an unauthenticated MQTT client can send partial CONNECT packets that cause the server to retain large incomplete packets in memory, leading to memory exhaustion. This issue is fixed in versions 2.14.3 and 2.12.12. No known exploits are reported in the wild.
References
- ubuntu.com/security/CVE-2026-58210 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-58210 (opens in a new tab)
- github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qg (opens in a new tab)
- github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7edfc0861 (opens in a new tab)
- github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862adefaf5 (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-2026-58210 (opens in a new tab)