What is CVE-2026-78135?

CVE-2026-78135 is a medium-severity vulnerability in Strongswan, classified under Improper Enforcement of Behavioral Workflow. CVSS score: 5.6/10. Published 2026-09-11.

How severe is CVE-2026-78135?

Medium severity. CVSS v3 base score is 5.6 out of 10.

Vulnerability in Strongswan

CVE-2026-78135

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 v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

Affected products

Strongswan

Weakness classification (CWE)

CWE-841 — Improper Enforcement of Behavioral Workflow

References

cve@mitre.org
cve@mitre.org

Frequently asked questions

What is CVE-2026-78135?: CVE-2026-78135 is a medium-severity vulnerability in Strongswan, classified under Improper Enforcement of Behavioral Workflow. CVSS score: 5.6/10. Published 2026-09-11.
How severe is CVE-2026-78135?: Medium severity. CVSS v3 base score is 5.6 out of 10.