CVE-2026-78133 Use after free in strongSwan

High 7.5 Published 11 Sep 2026 Updated 11 Sep 2026

A use-after-free in strongSwan's IKEv2 rekeying allows attackers to potentially execute code or cause denial of service.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-78133?

CVE-2026-78133 is a high-severity use after free vulnerability in strongSwan, published on 11 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

libcharon in strongSwan 6.0.0 through 6.0.7 has a use-after-free in IKEv2 rekeying collision handling.

Weakness: CWE-416

Which versions are affected by CVE-2026-78133?

It affects 1 product.

Products include Strongswan Strongswan.

How do I fix CVE-2026-78133?

Upgrade to a fixed version.

Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.

Is CVE-2026-78133 being exploited?

There is no known exploitation of CVE-2026-78133 in the wild and no public exploit code.

Sources

Also known as AZL-101829, DEBIAN-CVE-2026-78133, GHSA-wc93-h4m4-584v, MINI-2vjw-738h-fjx5, UBUNTU-CVE-2026-78133.