Resource exhaustion in Linuxfoundation Nats-server
CVE-2026-27571
NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The WebSockets handling of NATS messages handles compressed messages via the WebSockets negotiated compression. Prior to versions 2.11.2 and 2…
EPSS: 0.005 (38.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Linuxfoundation Nats-server
- Nats-io Nats-server — versions < 2.11.12, >= 2.12.0-RC.1, < 2.12.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
- security-advisories@github.com (Product, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2026-27571?
- CVE-2026-27571 is a medium-severity vulnerability in Linuxfoundation Nats-server, classified under Improper Handling of Highly Compressed Data (Data Amplification). CVSS score: 5.9/10. Published 2026-02-24.
- How severe is CVE-2026-27571?
- Medium severity. CVSS v3 base score is 5.9 out of 10.