CVE-2026-56853 Affecting nats package, versions <0.4.0-r5


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.59% (46th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-NATS-18803638
  • published15 Aug 2026
  • disclosed13 Aug 2026

Introduced: 13 Aug 2026

NewCVE-2026-56853  (opens in a new tab)

How to fix?

Upgrade Chainguard nats to version 0.4.0-r5 or higher.

NVD Description

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

When a server is configured to support unencrypted HTTP/2, it reads a few bytes from each new connection to see if they contain the HTTP/2 client preface. ReadHeaderTimeout is unexpectedly not being applied when doing this.

CVSS Base Scores

version 3.1