Quick answers
- Is CVE-2026-77206 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-77206 being exploited in the wild.
- How severe is CVE-2026-77206?
- High severity, with a CVSS score of 7.5, published 13 October 2026.
- Which products and versions are affected?
- Libreswan 5.3 and earlier.
- Is there a fix for CVE-2026-77206?
- Yes: fixed in Libreswan 5.4. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-77206 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-77206?
- Check whether you run Libreswan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: Libreswan 5.4
Technical details
A null pointer dereference exists in Libreswan's IKEv2 state machine within the EAP authentication handler, where ike->sa.st_eap is dereferenced without being checked for NULL. The vulnerability can be triggered by any IKEv2 connection regardless of EAP configuration, via a malicious IKE_AUTH packet sent over the network without prior authentication. Exploitation causes the pluto daemon to crash and restart; remote code execution is not possible, but repeated exploitation results in denial of service.
Affected products
- Libreswan Libreswan 5.3 and earlier
Timeline
- 2026-10-13: advisory