cvedb.io
CVE-2026-27571
MEDIUM · CVSS 5.9
EPSS exploitation probability: 0%
Published 2026-02-24T17:29:03.393 · Last modified 2026-06-17T10:27:19.650

Summary

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 2.12.3, the implementation bound the memory size of a NATS message but did not independently bound the memory consumption of the memory stream when constructing a NATS message which might then fail validation for size reasons. An attacker can use a compression bomb to cause excessive memory consumption, often resulting in the operating system terminating the server process. The use of compression is negotiated before authentication, so this does not require valid NATS credentials to exploit. The fix, present in versions 2.11.2 and 2.12.3, was to bounds the

Affected products

linuxfoundation — nats-server

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.