Improper Enforcement of Behavioral Workflow Affecting strongswan package, versions <5.9.5-2ubuntu2.8


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.42% (36th percentile)

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  • Snyk IDSNYK-UBUNTU2204-STRONGSWAN-19653986
  • published21 Sept 2026
  • disclosed11 Sept 2026

Introduced: 11 Sep 2026

CVE-2026-78135  (opens in a new tab)
CWE-841  (opens in a new tab)

How to fix?

Upgrade Ubuntu:22.04 strongswan to version 5.9.5-2ubuntu2.8 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream strongswan package and not the strongswan package as distributed by Ubuntu. See How to fix? for Ubuntu:22.04 relevant fixed versions and status.

libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because CREATE_CHILD_SA requests are mishandled, there can be an authentication bypass.

CVSS Base Scores

version 3.1