What is CVE-2026-33222?

CVE-2026-33222 is a medium-severity vulnerability in Nats-io Nats-server, classified under Improper Authorization. CVSS score: 4.9/10. Published 2026-03-25.

How severe is CVE-2026-33222?

Medium severity. CVSS v3 base score is 4.9 out of 10.

Auth bypass in Nats-io Nats-server

CVE-2026-33222

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, users with JetStream admin API access to restore one stream could restore to other stream names, impactin…

EPSS: 0.000 (1.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N.

Affected products

Nats-io Nats-server — versions < 2.11.15, >= 2.12.0-RC.1, < 2.12.6

Weakness classification (CWE)

CWE-285 — Improper Authorization

References

https://github.com/nats-io/nats-server/security/advisories/GHSA-9983-vrx2-fg9c (x_refsource_CONFIRM)
https://advisories.nats.io/CVE/secnote-2026-12.txt (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-33222?: CVE-2026-33222 is a medium-severity vulnerability in Nats-io Nats-server, classified under Improper Authorization. CVSS score: 4.9/10. Published 2026-03-25.
How severe is CVE-2026-33222?: Medium severity. CVSS v3 base score is 4.9 out of 10.