Improper Handling of Highly Compressed Data (Data Amplification) Affecting nats-top package, versions <0.6.3-r14


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.03% (10th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-NATSTOP-15352104
  • published26 Feb 2026
  • disclosed24 Feb 2026

Introduced: 24 Feb 2026

CVE-2026-27571  (opens in a new tab)
CWE-409  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

Upgrade Chainguard nats-top to version 0.6.3-r14 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nats-top package and not the nats-top package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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 decompression to fail once the message was too large, instead of continuing on. The vulnerability only affects deployments which use WebSockets and which expose the network port to untrusted end-points.

CVSS Base Scores

version 3.1