CVE intelligence

CVE-2026-77206

Vulnerability intelligence

Published Oct 13, 2026Sources checked Oct 21, 2026

7.5HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-77206 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 15, 2026

Release Notes

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-77206?

Libreswan's IKEv2 state machine has a null pointer dereference bug in the EAP handling code for authentication. As a result of inconsistency within the IKEv2 state machine code, this bug can be triggered by any IKEv2 connection, even if EAP is not configured at all.

The error is caused by a fall-through where it incorrectly dereferences ike->sa.st_eap which is NULL. A malicious IKE_AUTH packet can trigger this bug, meaning the peer does not need to be authenticated.

The bug results in a crash and restart of the pluto daemon. No remote code execution is possible.

Continued exploitation can cause a denial of service.

Source: NVD