CVE-2026-78135: High severity strongSwan libcharon vulnerability
Last updated 21 September 2026
Other sources
libcharon in strongSwan 5.9.7 through 6.0.7 mishandles behavioral workflow in the IKEv2 state machine. Because CREATECHILDSA requests are mishandled, there can be an authentication bypass.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 5.9.14-11 - Upgrade
Upgrade
debian/strongswanto a version that resolves this vulnerability.Fixed in 6.0.1-6+deb13u7Fixed in 6.1.0-2
Event History
Frequently Asked Questions
Which deployments are affected?
The affected component is libcharon in strongSwan versions 5.9.7 through 6.0.7. Deployments outside that stated range are not identified as affected by the provided data.
What level of attacker access is required?
The CVSS vector indicates the issue is remotely exploitable over the network and does not require attacker privileges or user interaction. Exploitation has high attack complexity.
What is the potential security impact?
Successful exploitation can bypass authentication in the IKEv2 workflow. The provided CVSS assessment rates confidentiality, integrity, and availability impact as low.