CVE-2026-56855 Affecting aactl package, versions <0.4.12-r75


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.38% (31st percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-AACTL-19531299
  • published4 Sept 2026
  • disclosed2 Sept 2026

Introduced: 2 Sep 2026

NewCVE-2026-56855  (opens in a new tab)

How to fix?

Upgrade Chainguard aactl to version 0.4.12-r75 or higher.

NVD Description

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

Previously, after a channel has been established, a malicious peer could send crafted messages that would deadlock the entire connection. Now, we handle all RFC 4254 channel messages; global requests are handled explicitly. Then, treat all other messages as a protocol error and tear the connection down instead of buffering and blocking.

CVSS Base Scores

version 3.1