Nats server: Prior to 2.14.3 and 2.12.8, message trace destination checks were applied to ordinary client connections
Affects nats-serverSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium · fixed in 2.14.3 : update nats-server when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 2.14.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA: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 2.12.8 or later, where this vulnerability is fixed. No other mitigation is indicated by the vendor advisory.
Description
CVE-2026-58254 is a permission check bypass vulnerability in NATS Server affecting leaf node connections related to message trace destinations. It allows a leafnode operator to send trace events to unauthorized subjects, which may disrupt normal message delivery or storage. The vulnerability affects versions prior to 2.14.3 and 2.12.8 and is fixed in those versions.
References
- ubuntu.com/security/CVE-2026-58254 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-58254 (opens in a new tab)
- github.com/nats-io/nats-server/security/advisories/GHSA-p3j5-5hrq-p75h (opens in a new tab)
- github.com/nats-io/nats-server/commit/cbe845932980b71563efac5cfa4cc751c88936cd (opens in a new tab)
- github.com/nats-io/nats-server/releases/tag/v2.12.8 (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-2026-58254 (opens in a new tab)