PT-2026-56566 · Nats.Io · Nats Server

Published 2026-07-08 · Updated 2026-07-08 · CVE-2026-58254

NVD

CVSS v4.0

5.3

Medium

Base vector

AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.8, message trace destination checks were applied to ordinary client connections but not consistently to messages arriving through leafnode connections, allowing a leafnode operator to send trace events to subjects that would not otherwise be permitted and to use trace-only behavior to prevent normal delivery or storage of affected messages. This issue is fixed in versions 2.14.3 and 2.12.8.

Fix

Incorrect Authorization

Weakness Enumeration

CWE-863

Related Identifiers

CVE-2026-58254

Affected Products

Nats Server

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2026-58254 · Security Note
• https://github.com/nats-io/nats-server/releases/tag/v2.12.8 · Note
• https://github.com/nats-io/nats-server/releases/tag/v2.14.3 · Note
• https://github.com/nats-io/nats-server/security/advisories/GHSA-p3j5-5hrq-p75h · Note
• https://github.com/nats-io/nats-server/commit/cbe845932980b71563efac5cfa4cc751c88936cd · Note