Auth bypass in Nats-Io Nats-Server

CVE-2025-30215

NATS-Server is a High-Performance server for NATS.io, the cloud and edge native messaging system. In versions starting from 2.2.0 but prior to 2.10.27 and 2.11.1, the management of JetStream assets happens with messages in the $JS. subject namespace in the system account; this is partially exposed into regular accounts to allow account holders to manage their assets. Some of the JS API requests were missing access controls, allowing any user with JS management permissions in any account to perform certain administrative actions on any JS asset in any other account. At least one of the unprotected APIs allows for data destruction. None of the affected APIs allow disclosing stream contents. This vulnerability is fixed in v2.11.1 or v2.10.27.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.1th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-30215: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-30215?
CVE-2025-30215 is a critical-severity vulnerability in Nats-Io Nats-Server, classified under Improper Authentication. CVSS score: 9.6/10. Published 2025-04-16.
How severe is CVE-2025-30215?
Critical severity. CVSS v3 base score is 9.6 out of 10.